| 1. |
- Schultheiss, Fredrik, et al.
(författare)
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Cost Optimization by Incremental Production Improvements of Metal Cutting Operations
- 2011
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Ingår i: [Host publication title missing]. ; , s. 540-547
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Konferensbidrag (refereegranskat)abstract
- The focus of this project has been to find a method on how to do production improvements systematically in the case of manufacturing by means of metal cutting operations. Typically every company determines their cutting data with the help of previous experiences as well as recommendations made by the tool manufacturers. These chosen cutting data may be the optimal settings for the specific operation although the probability for this is very slim. Some large companies have resources to investigate and find the optimum cutting data by themselves but this is usually not the case for SMEs. These companies need a clear and logical method on how to find the machining optimum while not causing too many delays or scraped parts during the normal production. The goal of this research was to find a method to incrementally optimize the production in terms of manufacturing costs of the machined parts in SMEs. The proposed method is illustrated by an analysis of the results obtained from a case study at a small Swedish company. The present work constitutes a good foundation for the optimization of the production process and thereby has a strong relevance toward the area of sustainable production.
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| 2. |
- Schultheiss, Fredrik, et al.
(författare)
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Machinability of duplex stainless steels - A study with focus on the tool wear behaviour
- 2011
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Ingår i: [Host publication title missing]. ; , s. 271-277
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Konferensbidrag (refereegranskat)abstract
- This article presents research done in order to analyse the machinability of duplex stainless steel with coated carbide tools during turning operations. Although duplex stainless steel has existed for about 70 years fairly little work has been published in the area of investigating the different aspects of the machining of these materials. In this research project three different kinds of duplex stainless steels and their properties have been examined. These materials where SAF 2507, SAF 2205 and LDX 2101 which together covers a large part of the duplex stainless steels that are commercially available today. This study focuses on analysing the tool wear behaviour in an attempt to better understand the actual wear patterns during machining, not only the more traditional ones that are in common use today. Some additional tests were also done in order to get a better understanding of the machinability of duplex stainless steel in general. Theories and concepts that are related to the analysing of machinability will be presented, most of which have been previously validated and in use for a long time. Adhesive wear of the cutting tool, in many cases severe, was to some extent found at all different cutting data investigated.
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| 3. |
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| 4. |
- Adolfsson, C, et al.
(författare)
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Cutting force model for multi-toothed cutting processes and force measurement equipment for face milling
- 1995
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 35:12, s. 1715-1728
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a mechanical cutting force model for multi-tooth cutting processes, where initial position errors in radial and axial direction, eccentricity and edge wear are taken into account. The cutting forces are presented for each individual cutting edge, and in a system of coordinates where one axis is parallel to the cutting speed vector at any instant. The process parameter cutting resistance, Cr is derived from the measured main cutting force FM. Cr should be regarded as a parameter since it is always increasing with decreasing values of theoretical chip thickness h1. A new way of measuring cutting forces in multi-tooth cutting processes is also presented. Eight cutting force components are measured on the tool close to each of the four cutting edges. The aroused signals are filtered, amplified, A/D-converted and put together in a serial stream for transmission through a hollow spindle via a fibre optic cable. The signals are sent from the rotating spindle to the frame of the machine over an air gap with Light Emitting Diodes. They are then demultiplexed, D/A-converted, and stored in a PC-based eight channel oscilloscope. With this measurement equipment it is possible to directly measure the cutting forces acting on each individual cutting edge.
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| 5. |
- Agic, Adnan, 1967-
(författare)
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Analysis of entry phase in intermittent machining
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cutting forces and vibrations are essential parameters in the assessment of a cutting process. As the energy consumption in the machining process is directly affected by the magnitude of the cutting forces it is of vital importance to design cutting edges and select process conditions that will maintain high tool performance through reduced energy consumption. The vibrations are often the cause of poor results in terms of accuracy, low reliability due to sudden failures and bad environmental conditions caused by noise. The goal of this work is to find out how the cutting edge and cutting conditions affect the entry conditions of the machining operation. This is done utilizing experimental methods and appropriate theoretical approaches applied to the cutting forces and vibrations. The research was carried out through three main studies beginning with a force build-up analysis of the cutting edge entry into the workpiece in intermittent turning. This was followed by a second study, concentrated on modelling of the entry phase which has been explored through experiments and theory developed in the first study. The third part was focused on the influence of the radial depth of cut upon the entry of cutting edge into the workpiece in a face milling application. The methodology for the identification of unfavourable cutting conditions is also explained herein. Important insights into the force build-up process help addressing the correlation between the cutting geometries and the rise time of the cutting force. The influence of the nose radius for a given cutting tool and workpiece configuration during the initial entry is revealed. The critical angle i.e. the position of the face milling cutter that results in unfavourable entry conditions has been explained emphasizing the importance of the selection of cutting conditions. Finally, the theoretical methods utilized for the evaluation of the role of cutting edge geometry within entry phase dynamics has been explored. This has revealed the trends that are of interest for selection of cutting conditions and cutting edge design.
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| 6. |
- Agic, Adnan, 1967-
(författare)
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Edge Geometry Effects on Entry Phase by Forces and Vibrations
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Intermittent machining is in general strongly related to the large impacts in the entry phase and related vibrations. The influence of the impact forces and vibrations on the cutting process is dependent on workpiece material, structural properties of the tool-workpiece system, cutting edge geometries and cutting parameters. Cutting forces adopt generally a periodic behaviour that gives rise to forced vibrations. In addition, self-induced vibrations may arise because of lowrigidity and insufficient damping in the tool-workpiece system at specific cutting parameters. The ability of the cutting tool to carry the loads during the entry phase and minimize the vibrations is often the key parameter for an effective machining operation.This research work is based on the experiments, analytical studies and modelling. It was carried out through six main studies beginning with a force build-up analysis of the cutting edge entry into the workpiece in intermittent turning. This was followed by a second study, concentrated on modelling of the entry phase which has partly been explored through experiments and theory developed in the first study.The third part was focused on the influence of the radial depth of cut upon the entry of the cutting edge into the workpiece in a face milling application. The methodology for the identification of unfavourable radial depth of cut is also addressed herein. Next, effects of the cutting edge on the vibrations in an end milling application were investigated. This study was related to a contouring operation with the maximum chip thickness in the entry phase when machining steel, ISO P material.The results of this work provide some general recommendations when milling this type of workpiece material. After that, the focus was set on the dynamic cutting forces in milling. The force developments over a tooth engagement in milling showed to be strongly dependent on the cutting edge geometry. A significant difference between highly positive versus highly negative geometry was found.The implication of this phenomena on the stress state in the cutting edge and some practical issues were analysed. Finally, the role of the helix angle on the dynamic response of a workpiece was investigated. The modelling technique using force simulation and computation of the dynamic response by means of modal analysis was presented. Extensive experimental work was conducted to compare the modelling and experimentally obtained results. The modelling results showed a similar trend as the experimental results. The influence of helix angle on the cutting forces and the dynamic response was explained in detail.The research conducted in this work contributes to the deeper understanding of the influence of the cutting edge geometry and the cutting parameters on the force build up process during the entry phase. The presented studies investigate the force magnitudes, force rates and dynamic behaviour of the tools and workpieces when machining at the challenging entry conditions. The methodologies applied are focused on the physical quantities as forces and vibrations rather than the experimental studies that evaluate tool life. The methods and results of the research work are of great interest for the design of the cutting tools and optimization of the cutting processes.
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| 7. |
- Agic, Adnan, et al.
(författare)
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Influence of radial depth of cut on dynamics of face milling application
- 2016
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Ingår i: The 7th International Swedish Production Symposium, SPS16, Conference Proceedings. - Lund : Swedish Production Academy. ; , s. 1-9
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Konferensbidrag (refereegranskat)abstract
- The choice of milling cutter geometry and appropriate cutting data for certain milling application is of vital importance for successful machining results. Unfavourable selection of cutting conditions might give rise to high load impacts that cause severe cutting edge damage. The radial depth of cut in combination with milling cutter geometry might under some circumstances give unfavourable entry conditions in terms of cutting forces and vibration amplitudes. This phenomenon originates from the geometrical features that affect the rise time of the cutting edge engagement into work piece at different radial depths of cut. As the radial depth of cut is often an important parameter, particularly when machining difficult to cut materials, it is important to explore the driving mechanism behind vibrations generation. In this study, acceleration of the work piece is measured for different radial depths of cut and cutting edge geometries. The influence of the radial depth of cut on the dynamical behaviour is evaluated in time and frequency domains. The results for different radial depths of cut and cutting geometries are quantified using root mean square value of acceleration. The outcome of this research study can be used both for the better cutting data recommendations and improved tool design.
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| 8. |
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| 9. |
- Agmell, Mathias, et al.
(författare)
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A fully coupled thermomechanical two-dimensional simulation model for orthogonal cutting: formulation and simulation
- 2011
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Ingår i: Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture. - : SAGE Publications. - 0954-4054 .- 2041-2975. ; 225:B10, s. 1735-1745
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Tidskriftsartikel (refereegranskat)abstract
- In this paper a fully coupled thermomechanical two-dimensional simulation model for orthogonal cutting is presented. The model is based on the arbitrary Lagrangian-Eulerian formulation with the remeshing technique. The material model used for the workpiece material includes Johnson-Cook plasticity, and as the chip separation criterion the Johnson-Cook damage law is employed. The different friction zones are modelled by the Coulomb friction law with a maximum limit for the friction. The capability of the model to represent the cutting process realistically is validated by performing simulations for different feed depths. The model is validated by comparison of the simulated values and measured experimental data for several different important process parameters, such as the feed force, the cutting force, the chip thickness ratio, the relative deformation widths, and the temperature distribution. The results from the simulations showed very good agreement with the experimental data.
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| 10. |
- Agmell, Mathias, et al.
(författare)
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A numerical and experimental investigation of the deformation zones and the corresponding cutting forces in orthogonal cutting
- 2011
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Ingår i: Advanced Materials Research. - 1022-6680 .- 1662-8985. - 9783037850954 ; 223, s. 152-161
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Konferensbidrag (refereegranskat)abstract
- Abstract in UndeterminedThis study are focused on the deformation zones occurring in the work piece in a machining process and the corresponding cutting forces. The fully coupled thermo-mechanical FE-model for orthogonal cutting, developed in [1] is utilized. The work piece material is modeled with Johnson-Cook plasticity including damage formulation. Simulations for different feed depths were performed. The cutting forces, the chip thickness ratio and the deformation widths were determined experimentally by the quick-stop images and a force measurements. The results from the simulations have been compared to experimental data for the cutting forces and the chip thickness ratio as a function of the theoretical chip thickness.
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| 11. |
- Agmell, Mathias, et al.
(författare)
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Development of a simulation model to study tool loads in pcBN when machining AISI 316L
- 2018
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Ingår i: International Journal of Advanced Manufacturing Technology. - : Springer Science and Business Media LLC. - 0268-3768 .- 1433-3015. ; 96:5-8, s. 2853-2865
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the development of a FE-simulation model to predict the mechanical stresses and thermal loads that a cutting tool of polycrystalline cubic boron nitride (pcBN) is subjected to, when machining AISI 316L. The serrated chip formation of AISI 316L has a major impact on the periodic loads acting on the cutting tool. Therefore, it is vital to correctly model this serrated chip formation. One of the major difficulties with FE-simulations of metal cutting is that the extreme deformations in the workpiece material, often leads to a highly distorted mesh. This paper uses the Coupled Eulerian-Lagrangian (CEL) formulation in Abaqus/Explicit, where the workpiece is modelled with the Eulerian formulation and the cutting tool by the Lagrangian one. This CEL formulation enables to completely avoid mesh distortion. To capture the chip serration process, the workpiece material is described with the Johnson-Cook damage model. The FE-simulation results are validated via comparison of the modelled cutting forces, chip serration frequency, and contact length against experimental ones.
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| 12. |
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| 13. |
- Agmell, Mathias, et al.
(författare)
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Identification of plasticity constants from orthogonal cutting and inverse analysis
- 2014
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Ingår i: Mechanics of Materials. - : Elsevier BV. - 0167-6636. ; 77, s. 43-51
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this work is that from experimental determined cutting process parameters be able to predict the plasticity input constants to Finite Element Method (FEM) models. In the present study the Johnson-Cook constitutive model constants are determined on the basis of cutting process parameters in orthogonal cutting and by use of inverse analysis. Previously established links between Johnson-Cook constitutive model constants and cutting process parameters in the cutting process such as primary cutting force and chip compression ratio is used serve as a starting point in the inverse analysis. As a reference material AISI 4140 has been chosen in this study, which is a tempered steel. The Johnson-Cook constitutive model constants in the reference material are being changed within an interval of ±30 %. The inverse analysis is performed using a Kalman filter. The material model for the reference material is validated on the basis of the experimental results in previous work. The model showed to predict the cutting process parameters with a high level of accuracy. The predicted Johnson-Cook constitutive model constants in the present study achieve an error between simulated- and experimental cutting process parameters of maximum 2%. The method described in this study is not limited to identify Johnson-Cook constitutive model constants, but the method can also be used for other constitutive models. The same applies to the process itself and the selected cutting process parameters, but orthogonal cutting has been used to illustrate and validate this method.
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| 14. |
- Agmell, Mathias, et al.
(författare)
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Investigation of mechanical and thermal loads in pcBN tooling during machining of Inconel 718
- 2020
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Ingår i: International Journal of Advanced Manufacturing Technology. - : Springer Science and Business Media LLC. - 0268-3768 .- 1433-3015. ; 107, s. 1451-1462
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates machining superalloy Inconel 718 with polycrystalline cubic boron nitride (pcBN) tooling both numerically and experimentally. Particular attention is given to mechanical and thermal stresses in the cutting tool arising from segmented chip formation and associated forces and temperatures. The temperature dependence of the mechanical properties of pcBN has been investigated and incorporated into a numerical model. In order to capture the dynamic loads due to a serrated chip formation, the Johnson–Cook damage model has been used. The extreme deformations during a machining process often results in a numerical difficulties due to a distorted elements. This paper uses the coupled Eulerian–Lagrangian (CEL) formulation in Abaqus/Explicit, where the workpiece is modelled with the Eulerian formulation and the cutting tool by the Lagrangian one. This CEL formulation enables to completely avoid mesh distortion. The finite element simulation results are validated via comparison of the modelled static and dynamic cutting forces and thermal loads induced into the cutting tool. The numerical model predicts a temperature of 1100–1200 ∘C at the cutting interface, which is in line with experimental determined data. The principal stresses at the rake up to 300 MPa are recorded, whereas higher level of stresses up to 450 MPa are found in the notch region of the tool, well correlated with experimental observation.
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| 15. |
- Agmell, Mathias, et al.
(författare)
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Modelling Subsurface Deformation in High Speed Machining of Inconel 718
- 2012
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Konferensbidrag (refereegranskat)abstract
- Abstract in UndeterminedTraditionally, the development and optimization of the machining process with regards to the sub-surface deformation is done through experimental method which is often expensive and time consume. This paper presents the development of a FE-simulation model to predict the depth of sub-surface deformation induced in the high speed machining of Inconel 718 by use of whisker-reinforced ceramic tool. The effects of cutting parameters and geometry on sub-surface deformation will be simulated by developed FE model. In addition to FE model, the experimental study was made to validate the results of FE model. Characterization of sub-surface deformation produced under different machining parameters and tool conditions was made by EBSD and in the cutting and feed directions.
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| 16. |
- Agmell, Mathias, et al.
(författare)
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The influence of tool micro-geometry on stress distribution in turning operations of AISI 4140 by FE analysis
- 2017
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Ingår i: International Journal of Mechanical Sciences. - : Springer Science and Business Media LLC. - 1879-2162. ; 89:9-12, s. 3109-3122
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Tidskriftsartikel (refereegranskat)abstract
- Abstract This paper aims to gain a better understanding of the impact different micro-geometries has on stress distribution in cutting tools. Both principal and effective stress distribution are studied since these quantities have a major impact on the occurrence of damages in the cutting tool such as crack formation, flaking, chipping, breakage and plastic deformation. The development of a stagnation zone has also been investigated and the effect tool micro-geometries have on this zone. A finite element model has been developed which enables the examination of these aspects, in detail. The model was able to predict these metal cutting phenomena with high accuracy. Cutting forces is within the standard deviation of experimental results, stress distributions and the stagnation zone is also simulated correctly indicated by experimental results. This study has shown that the micro-geometries of the cutting tool have a great potential in order to reduce the maximal tensile/principal stress. This research work also shows that the size of the stagnation zone can be controlled by micro-geometries on the cutting tool, which can have an effect on the wear on the cutting edge.
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| 17. |
- Agmell, Mathias, et al.
(författare)
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The Influence the Uncut Chip Thickness has on the Stagnation Point in Orthogonal Cutting
- 2017
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Ingår i: 16th CIRP Conference on Modelling of Machining Operations (16th CIRP CMMO). - : Elsevier BV. - 2212-8271. - 9781510842762 ; 58, s. 13-18
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Konferensbidrag (refereegranskat)abstract
- The effect of cutting data on the stagnation zone of a machining operation is of great interest since it governs the material flow around the cutting edge. The material flow has a significant influence on the mechanical properties of the machined surface. This paper presents a numerical model that is able to determine the effect that the uncut chip thickness has on the stagnation zone and the connection between the stagnation zone and the deformation layer in the machined subsurface.
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| 18. |
- Agmell, Mathias, et al.
(författare)
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The link between plasticity parameters and process parameters in orthogonal cutting
- 2013
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Ingår i: 14th CIRP Conference on Modeling of Machining Operations (CIRP CMMO). - : Elsevier BV. - 2212-8271. ; 8, s. 224-229
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Konferensbidrag (refereegranskat)abstract
- In the present study the plasticity parameters in the Johnson Cook plasticity model are determined on the basis of process parameters in orthogonal cutting by use of inverse analysis. Previously established links between material parameters and process parameters in the cutting process such as chip thickness ratio, cutting forces, temperatures, deformation zones, is used serve as a starting point in the inverse analysis. The material AISI 4140 is simulated using the model employed in [1], the Johnson Cook parameters being changed within an interval of ±30 %. The inverse analysis is performed using a Kalman filter. The material model for the reference point is validated on the basis of the experimental results in [1], the model being shown to predict the process parameters with a high level of accuracy. The attempt is made to establish a link for materials having cutting process characteristics that are similar between certain process parameters and the Johnson Cook parameters in order to be able to predict the input parameters to FEM models using experimental data from a cutting process.
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| 19. |
- Andersson, Carin, et al.
(författare)
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Bandsawing. Part I: cutting force model including effects of positional errors, tool dynamics and wear
- 2000
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 41:2, s. 227-236
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a mechanical cutting force model for bandsawing. The model describes the variation in cutting force between individual teeth and relates it to initial positional errors, tool dynamics and edge wear. Bandsawing is a multi-tooth cutting process, and the terminology of the cutting action is discussed and compared with other cutting processes. It will also be shown that the setting pattern and the preset feed govern the cutting data.
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| 20. |
- Andersson, Carin, et al.
(författare)
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Bandsawing. Part II: detecting positional errors, tool dynamics and wear by cutting force measurement
- 2000
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Ingår i: International Journal of Machine Tools & Manufacture. - 0890-6955. ; 41:2, s. 237-253
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a method for measuring individual cutting forces during bandsawing. Methods for detecting errors in cutting edge positions, tool dynamics during machining and geometry changes due to wear have also been developed. The experimental studies that we have conducted show that the cutting forces vary during the tool engagement. These variations in force were then quantified using a previously developed cutting force model for multi-tooth cutting processes including effects of positional errors, tool dynamics and wear.
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| 21. |
- Andersson, Carin, et al.
(författare)
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Experimental studies of cutting force variation in face milling
- 2011
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Ingår i: International Journal of Machine Tools & Manufacture. - : Elsevier BV. - 0890-6955. ; 51:1, s. 67-76
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this paper is to present a developed cutting force model for multi-toothed cutting processes, including a complete set of parameters influencing the cutting force variation that has been shown to occur in face milling, and to analyse to what extent these parameters influence the total cutting force variation for a selected tool geometry. The scope is to model and analyse the cutting forces for each individual tooth on the tool, to be able to draw conclusions about how the cutting action for an individual tooth is affected by its neighbours. A previously developed cutting force model for multi-toothed cutting processes is supplemented with three new parameters; eccentricity of the spindle, continuous cutting edge deterioration and load inflicted tool deflection influencing the cutting force variation. A previously developed milling force sensor is used to experimentally analyse the cutting force variation, and to give input to the cutting force simulation performed with the developed cutting force model. The experimental results from the case studied in this paper show that there are mainly three factors influencing the cutting force variation for a tool with new inserts. Radial and axial cutting edge position causes approximately 50% of the force variation for the case studied in this paper. Approximately 40% arises from eccentricity and the remaining 10% is the result of spindle deflection during machining. The experimental results presented in this paper show a new type of cutting force diagrams where the force variation for each individual tooth when two cutting edges are engaged in the workpiece at the same time. The wear studies performed shows a redistribution of the individual main cutting forces dependent on the wear propagation for each tooth.
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| 22. |
- Andersson, Carin, et al.
(författare)
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Grinding or shaving - economic decision support in the production of gears
- 2014
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Ingår i: ; , s. 1-8
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Konferensbidrag (refereegranskat)abstract
- This paper describes a case study at an automotive company with the purpose ov developing an economically based decision support tool, for strategic decision about wheather to chose grinding or shaving as a finishing method in gear manufacturing. In the study different cost models are compared regarding input parameters in alignment with the required input data required to make a decision. With the performance driven cost model used during the analysis, shaving was shown to be the most cost efficient finishing method.
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| 23. |
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| 24. |
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| 25. |
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| 26. |
- Andersson, Carin, et al.
(författare)
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Manufacturing costs as a decisionsupport in production developoment and relocation issues - a case study at a supplier to the automotive industry
- 2014
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Ingår i: ; , s. 1-10
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Konferensbidrag (refereegranskat)abstract
- This paper will present a case study at a Swedish subcontractor, were a performance driven manufacturing cost model is used to analyse different production development scenarios in relation to sourcing. The result shows that production performance in terms of downtime, speed rate and quality losses will have a significant impact on manufacturing costs. The cost model was used to obtain cost scenarios for different offshoring alternatives serving as a decision support for the company management. Based on these scenarios they decided not to offshore production, instead they realized the potential of developing the Swedish site according to the proposed scenario.
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| 27. |
- Andersson, Carin, et al.
(författare)
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Modeling of maintenance costs
- 2011
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Konferensbidrag (refereegranskat)abstract
- Abstract in Undetermined Increased global competition demands for increased manufacturing costs awareness. Maintenance activities and strategies have been studied extensively, but few studies discuss maintenance costs. This paper presents a model for calculating performance-driven manufacturing costs (in currency/piece), including parameters for determining the maintenance costs in relation to the total manufacturing costs. This study focus on developing an existing manufacturing part cost model involving parameters driving maintenance costs. A proposal of the allocation of different maintenance activities to different costs parameters is discussed together with the utilization of the model in an industrial case study.
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| 28. |
- Bello bermejo, Juan manuel, et al.
(författare)
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A Methodology Using Monte-Carlo Simulation on Nanoindentation Deconvolution for Metal Classification
- 2024
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Ingår i: Proceedings of the 11th Swedish Production Symposium (SPS2024). - 2352-751X .- 2352-7528. - 9781643685113 - 9781643685106 ; 52, s. 613-627
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Bokkapitel (refereegranskat)abstract
- This paper investigates a methodology for the precise statistical deconvolution of hardness properties within various metallic matrix multiphase materials. The central focus is on accurately characterizing mechanical behaviour in the context of complex materials. To meet these objectives, we implemented an approach involving nanoindentation analyses of the selected materials. This technique allowed for the creation of material profiles based on micromechanical properties. Statistical cumulative density function (CDF) deconvolution was employed to disentangle the complex distributions of multiphase material hardness using cross-validation. Throughout the course of this study, several multicomponent CDF combinations were tested, including Weibull, Exponential, and Gaussian distributions. This approach challenges the conventional practice of assuming multiple Gaussian distributions of hardness, revealing the limitations of this approach. In addition, Monte-Carlo simulations were harnessed to generate probability density functions (PDFs) that capture the intricate footprint variations in hardness profiles. By implementing our methodology, we strive to offer a comprehensive and refined approach to materials analysis. This potential for differentiation has the significant implication of investigating the impact of impurities and trace elements on the mechanical properties and thus, machinability of metal materials. The ultimate aim is to enhance their recyclability, thereby advancing the principles of the circular economy and contributing to the sustainable development goals. Our study thus underscores the profound impact of material analysis on environmental sustainability and the efficient use of resources, while offering a fresh perspective on the role of statistics in materials science.
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| 29. |
- Bjerke, Axel, et al.
(författare)
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Onset of the degradation of CVD alpha-Al2O3 coating during turning of Ca-treated steels
- 2021
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Ingår i: Wear. - : Elsevier BV. - 0043-1648 .- 1873-2577. ; 477
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Tidskriftsartikel (refereegranskat)abstract
- The ability to control the shape, distribution and composition of non-metallic inclusions has had an important impact on many aspects of steel making. One such impact is on the machinability. Ca-treatments have shown to be able to reduce the abrasiveness of oxide inclusions, improve chip-breaking and lead to formation of deposits that reduce tool wear. However, machining Ca-treated steels with Al2O3 coated cemented carbide tools has not been as advantageous as expected. This study investigates the mechanisms behind the anomalous wear of Al2O3 coatings when turning soft Ca-treated steels. Longitudinal turning tests at a range of speeds (vc = 100-600 m/min) show rapid localized degradation of the Al2O3 coating limited to the sliding zone. Detailed analysis of the degradation mechanisms was performed using scanning and transmission electron microscopy. The results demonstrate a presence of chemical interactions between the alumina coating and non-metallic inclusions. The interaction resulted in the formation of mainly calcium aluminates and partly alumina-magnesia spinel. In-operando infrared thermography measurements indicate cutting temperatures of 850-1000 degrees C. Thermodynamic calculations give that CaO and MgO readily reacts with Al2O3, while the reaction with CaS requires presence of additional oxygen at these cutting conditions. Additional turning experiments investigate the influence of oxygen by controlling the cutting environment by adding oxygen (compressed air) or removing oxygen (supply argon). These additional tests show that the presence of additional oxygen has a limited impact on the possible Ca-Al2O3 interaction. This demonstrat a potential for further machinability improvements by controlling the chemical interaction between Ca and Mg based non-metallic inclusions and alumina coatings.
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| 30. |
- Bushlya, Volodymyr, et al.
(författare)
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Characterization of White Layer Generated when Turning Aged Inconel 718
- 2011
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Ingår i: Procedia Engineering. - : Elsevier BV. - 1877-7058. ; 19, s. 60-66
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Konferensbidrag (refereegranskat)abstract
- Abstract in UndeterminedWhite layer formation is considered as a part of minimum array of parameters characterizing surface integrity of the machined product. The paper is aimed on identification and characterization of white layer generated when finish turning aged Inconel 718 with Al2O3-SiCw ceramic tools under different cutting conditions, tool wear and coolant application. As expected intensity of white layer formation was proportional to cutting speed and tool wear. High resolution transmission electron microscopy (HRTEM) performed on white layer revealed formation of nanostructured material with grain size of 50-150 nm. Long-term ultrasonic-assisted etching of white layer allowed to uncover its morphology, where subsequent AFM measurements confirmed HRTEM findings. Observations by high resolution SEM provided evidence that gamma' Ni-3(Al,Ti) phase remained intact. (C) 2012 Published by Elsevier Ltd. Selection and peer-review under responsibility of Prof. E. Brinksmeier
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| 31. |
- Bushlya, Volodymyr, et al.
(författare)
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Effect of ageing on machining performance of grey cast iron and its compensation by cutting speed management
- 2024
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Ingår i: CIRP Annals. - 0007-8506.
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Tidskriftsartikel (refereegranskat)abstract
- Grey cast iron is known for its poor machinability directly after casting, but attains excellent machining performance after ageing. The present work explores the impact of cutting speed on the performance of pcBN machining for non-aged material. Findings suggest that tool wear can be minimized by identifying an optimal cutting speed that supports the formation of a stable Al2O3 and MnS build-up layer (BUL). Insufficient BUL protection accelerates pcBN wear by diffusion, while at very high speeds protective Al2O3 is replaced by weaker (Fe,Mn)2SiO4 and (Fe,Mn)O, and oxidation accelerates tool wear. The higher mechanical properties of aged GCI facilitate generation of high enough temperatures for stable deposition of Al2O3 BUL.
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| 32. |
- Bushlya, Volodymyr, et al.
(författare)
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Effect of Cutting Conditions on Machinability of Superalloy Inconel 718 During High Speed Turning with Coated and Uncoated PCBN Tools
- 2012
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Ingår i: 45th CIRP Conference on Manufacturing Systems 2012. - : Elsevier BV. - 2212-8271. - 9781627485128 ; 3, s. 370-375
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Konferensbidrag (refereegranskat)abstract
- Inconel 718, an efficient superalloy for energy and aerospace applications, is currently machined with cemented carbide tools at low speed (vc≈60 m/min) due to its unfavorable mechanical and thermal properties. The article presents results of superalloy machinability study with uncoated and coated PCBN tools aiming on increased speed and efficiency. Aspects of tool life, tool wear and surface integrity were studied. It was found that protective function of the coating, increasing tool life up to 20%, is limited to low cutting speed range. EDX and AFM analyses suggested dominance of chemical and abrasive wear mechanisms. Residual stress analysis has shown advantageous compressive surface stresses.
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| 33. |
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| 34. |
- Bushlya, Volodymyr, et al.
(författare)
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Effects of Cutting Speed when Turning Age Hardened Inconel 718 with PCBN Tools of Binderless and Low-CBN Grades
- 2013
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Ingår i: Machining Science and Technology. - : Informa UK Limited. - 1091-0344 .- 1532-2483. ; 17:4, s. 497-523
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Tidskriftsartikel (refereegranskat)abstract
- Application of polycrystalline cubic boron nitride (PCBN) tools as an alternative for ceramic and cemented carbide tools in machining superalloys has been frequently identified as a solution for enhancing process efficiency but only a limited number of studies has been done in this area. The current study explores the effect of the cutting speed, which was varied in a wide range (2-14m/s), on machinability of age hardened Inconel 718 with PCBN tools. Performance of binderless PCBN grade and grade with low-cBN content was evaluated in terms of tool life, tool wear, cutting forces and surface quality. Chip formation and process dynamics were analyzed as well. It was found that low-cBN grade provided 70-90% better surface finish and tool life than the binderless at moderate speeds (5-8m/s). Performance of both grades at low and high speed ranges was non-satisfactory due to notching and flaking respectively. At low cutting speed adhesive wear plays a major role while as the speed increases a chemical wear becomes dominant.
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| 35. |
- Bushlya, Volodymyr, et al.
(författare)
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Influence of oxygen on the tool wear in machining
- 2018
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Ingår i: CIRP Annals - Manufacturing Technology. - : Elsevier BV. - 0007-8506. ; 67:1, s. 79-82
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Tidskriftsartikel (refereegranskat)abstract
- High temperatures generated in machining are known to facilitate oxidation wear. A controlled atmosphere chamber was developed to investigate the effects of oxygen on tool wear and high speed machining tests were conducted on air and in argon. Cemented carbide, cermet and cubic boron nitride tooling was used on alloyed steel, hardened tool steel and superalloy Alloy 718. Machining in argon resulted in higher flank wear, higher cutting forces, and larger tool–chip contact length on the rake face. However, in hard machining, argon atmosphere reduced rake cratering. Transmission electron microscopy of tools worn on air showed formation of nanocrystalline Al2O3 film on the rake when machining aluminium containing Alloy 718, while no oxide films was detectable in the other cases.
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| 36. |
- Bushlya, Volodymyr, et al.
(författare)
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Modeling and experimentation on multistage work-hardening mechanism in machining with nose-radiused tools and its influence on machined subsurface quality and tool wear
- 2014
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Ingår i: International Journal of Advanced Manufacturing Technology. - : Springer Science and Business Media LLC. - 0268-3768 .- 1433-3015. ; 73:1-4, s. 545-555
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Tidskriftsartikel (refereegranskat)abstract
- The paper reports on the modeling and respective experimental validation for the formation of the machined subsurface layer in turning with nose-radiused and round tools. An experimental work on the mechanisms of work-hardening of the machined surface and related wear of the cutting tools was conducted for high-speed turning of aged Inconel 718 with whisker-reinforced alumina tools. The model shows that multiple deformations of the machined surface occur when machining with small feeds and tools with large nose radius, thus changing the mechanics of surface formation. Experimental results confirm the localized increase in subsurface hardness in the vicinity of the tool tip. The variation in the degree of work-hardening and the extent of the area affected by it fully agree with the predictions of the model. The model also shows that a significant part of the cutting tool may cut through the extra work-hardened material. Tool wear tests show that the local increase in workpiece hardness results in a localized increase in the wear rate of the cutting tools.
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| 37. |
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| 38. |
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| 39. |
- Bushlya, Volodymyr, et al.
(författare)
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On the Analytical Representation of Chip Area and Tool Geometry when Oblique Turning with Round Tools. Part 1: Chip Area Parameters under Variation of Side and Back Rake Angle
- 2015
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Ingår i: 15th CIRP Conference on Modelling of Machining Operations (15TH CMMO). - : Elsevier BV. - 2212-8271. ; 31, s. 417-422
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Konferensbidrag (refereegranskat)abstract
- Chip area parameters, such as undeformed chip thickness, equivalent chip thickness, contact edge length, etc., along with tool angles are among defining for the mechanical and thermal conditions of the cutting process. This paper considers the case of external turning with a round insert under variation, in wide range, of back and side rake angles and their influence on the main chip area and surface roughness parameters. Influence of other process variables, such as feed, depth-of-cut and nose radius, is also studied. The developed analytical models and algorithms allow, not only to study the fundamental relationships, but to apply them in the design of new tools for conventional and rotary turning.
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| 40. |
- Bushlya, Volodymyr, et al.
(författare)
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On the Analytical Representation of Chip Area and Tool Geometry when Oblique Turning with Round Tools. Part 2: Variation of Tool Geometry along the Edge Line
- 2015
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Ingår i: 15th CIRP Conference on Modelling of Machining Operations (15TH CMMO). - : Elsevier BV. - 2212-8271. ; 31, s. 423-428
-
Konferensbidrag (refereegranskat)abstract
- This paper presents the models, analytical equations and results of analysis for determination of major cutting edge, orthogonal and normal clearance and rake angles, and cutting edge inclination angle. The analysis is carried for variable side and back rake angles used by the tool manufacturers and a corresponding variation of the geometry along the edge line for the case of round tools. The influence of tool nose radius, chamfer/chipbreaker angle and depth-of-cut was considered as well. Significant variation in orthogonal geometry from that stated in catalogues was found in most cases. The developed analytical solutions and algorithms allow the establishment of fundamental geometrical relationships and giving a correct prediction when developing new tools for conventional and rotary turning. (C) 2015 The Authors. Published by Elsevier B.V.
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| 41. |
- Bushlya, Volodymyr, et al.
(författare)
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Performance and wear mechanisms of whisker-reinforced alumina, coated and uncoated PCBN tools when high-speed turning aged Inconel 718
- 2013
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Ingår i: International Journal of Advanced Manufacturing Technology. - : Springer Science and Business Media LLC. - 0268-3768 .- 1433-3015. ; 66:9-12, s. 2013-2021
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedInconel 718, an efficient superalloy for energy and aerospace applications, is currently machined with cemented carbide tools at low speed (vc≈60 m/min) due to its unfavorable mechanical and thermal properties. The article presents results of a study of superalloy machinability with whisker reinforced alumina, uncoated and coated PCBN tools. Turning of age hardened Inconel 718 (45 HRC) was done under high speed machining conditions (vc=250…350 m/min). Aspects of tool life, tool wear and generated surface quality were studied. Application of uncoated PCBN tools resulted in surface quality and force level superior to other tool materials. Considerable side-flow of workpiece material was found to affect surface quality, especially for coated PCBN and ceramic tools. It was found that protective function of the coating, which increases the tool life up to 20%, is limited only to low cutting speed range. EDX and AFM analyses suggested dominance of chemical and abrasive wear mechanisms. EDX mapping of worn tools pointed absence of diffusional wear for PCBN tools and intensive degradation of whisker reinforcement in ceramic tools due to diffusion of Ni, Fe and Cr.
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| 42. |
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| 43. |
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| 44. |
- Bushlya, Volodymyr, et al.
(författare)
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Tool wear and tool life of PCBN, binderless cBN and wBN-cBN tools in continuous finish hard turning of cold work tool steel
- 2014
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Ingår i: Journal of Superhard Materials. - 1934-9408. ; 36:1, s. 49-60
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Tidskriftsartikel (refereegranskat)abstract
- The paper presents the results of comparative study of performance of cutting tools made of ceramic-bound, binderless cBN, and wBN-cBN tool materials. The tool performance was assessed by tool wear-resistance, values of cutting forces, parameters of machined surface quality, and the state of sub-surface layer generated in continuous turning of hardened cold work tool steel. The tests were carried out under conditions of high speed machining (v (c) = 120-180 m/min) both with and without a coolant. The best tool performance by the above-mentioned criteria is provided by a low-cBN material with ceramic binder.
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| 45. |
- Bushlya, Volodymyr, et al.
(författare)
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Wear mechanisms of silicon carbide-whisker-reinforced alumina (Al2O3-SiCw) cutting tools when high-speed machining aged Alloy 718
- 2013
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Ingår i: International Journal of Advanced Manufacturing Technology. - : Springer Science and Business Media LLC. - 0268-3768 .- 1433-3015. ; 68:5-8, s. 1083-1093
-
Tidskriftsartikel (refereegranskat)abstract
- The paper is aimed at the identification and characterization of wear mechanisms of SiC whisker-reinforced alumina when turning aged Alloy 718 under different cutting conditions and when machining dry and with coolant. Secondary and backscatter electron microscopy accompanied by focus ion beam milling and EDX techniques were used for analysis of worn-out tools. Notch wear on the major cutting edge was found to consist of two notches: depth-of-cut notch and secondary notch located outside the chip area. The last was found to be governed by adhesion and attrition associated with adverse chip flow conditions. Formation of a minor notch was related to attrition by the defects found on the machined surface. Diffusion of Ni, Fe, and Cr into SiC whiskers was found to degrade them and facilitate adhesion. Chemical wear mechanisms were found to be responsible for degradation and decomposition of whiskers and formation of tribolayer on tool surfaces, which in turn was related to the reduced adhesion of Alloy 718 on the tool. Cracking on the tool rake and localized plastic deformation were found to further accelerate tool deterioration.
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| 46. |
- Bushlya, Volodymyr, et al.
(författare)
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Wear mechanisms of uncoated and coated cemented carbide tools in machining lead-free silicon brass
- 2017
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Ingår i: Wear. - : Elsevier BV. - 0043-1648. ; 376-377, s. 143-151
-
Tidskriftsartikel (refereegranskat)abstract
- Free-machining brass containing 2–3% of lead is a preferred industrial material as it shows excellent machinability where low cutting forces, short chips and reduced tool wear are attained. However this addition of lead, a highly toxic and hazardous material, leads to health and environmental issues. Alternative lead-free brasses are known for poor chip control and accelerated tool wear. The current study focuses on wear mechanisms of uncoated and coated cemented carbide tools when high-speed machining lead-free CuZn21Si3P silicon brass. The study shows that severe crater formation on the rake is the dominant tool failure mode. Microscopy observations indicate the diffusion wear mechanism to be driven by diffusion of cobalt binder into the chips and minor cross-diffusion of copper and zinc. Loss of the binder in cemented carbide is accompanied by adhesive pluck-out of WC grains. As a way to hinder the loss of Co, the diffusion preventing capacity of a-C:H diamond like carbon and (Ti,V,Zr,Nb,Hf,Ta)N nitride coating were tested. SEM, EDX and TEM data show that formation of amorphous SiO2 and stoichiometric β-SiAlON stable layers was observed on the nitride coating, thus preventing diffusional tool wear. O-rich and N-rich glassy amorphous layers in Si-Al-O-N system with ZnS inclusions were found on the DLC coating. Partial delamination of the DLC coating and removal of the glassy phases resulted in localized crater formation associated with diffusional wear.
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| 47. |
- Can, Antionette
(creator_code:cre_t)
-
Polycrystalline cubic boron nitride material
- 2023
-
Patent (övrigt vetenskapligt/konstnärligt)abstract
- This disclosure relates to a polycrystalline cubic boron nitride, PCBN, material that includes a binder matrix material containing nitride compounds. The nitride compounds are selected from HfN, VN, and/or NbN.
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| 48. |
- Cedell, Tord, et al.
(författare)
-
New advances in soft magnetic materials - properties of moulded flux conductors in inductors and electrical motors
- 2009
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Konferensbidrag (refereegranskat)abstract
- A new technology has emerged the last decade, based on a new group of materials; Soft Magnetic Composites (SMC), instead of laminated steel that facilitates production of products with more integrated, smaller, lighter, less costly and highly efficient electromagnetic machines. The application of this technology is a change of paradigm regarding integrated design and energy efficiency. This article describes a new group of SMC’s; Soft Magnetic Mouldable Composites (SM2C). With this material it is possible to produce electromagnetic components, using rotational- or gravital moulding technology, RotoCast. This new production method allows for integration of parts, coils etc, but also has a potential for automated low cost and high rate production. It is possible to reach impressive magnetic, mechanic and thermal properties in rotation moulded parts. High performance inductors and electrical motors has been produced by RotoCast and evaluated. The maximum permeability of SM2C is in the order of 30. This is ideal for inductors, since the storage of reactive energy is distributed uniformly. The total production cost of this type of inductors can be very low compared to conventional ferrite/litz solutions. Since the high frequency magnetization losses are low and the thermal conduction is considerable, there will be no hot-spots. For motors, the low permeability gives lower torque compared to conventional laminated motor structures. This is compensated by increasing the radius of the motor, and since the high-frequency magnetization losses are low the number of poles can be made very high, thus reducing the magnetic material giving the motor high torque-to-weight ratio.
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| 49. |
- Chen, Ling, et al.
(författare)
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Analysis of In Situ Mechanical Properties of Phases in High-Alloyed White Iron Measured by Grid Nanoindentation
- 2015
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Ingår i: Journal of Materials Engineering and Performance. - : Springer Science and Business Media LLC. - 1059-9495 .- 1544-1024. ; 24:10, s. 4022-4031
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Tidskriftsartikel (refereegranskat)abstract
- The paper presents an analysis of the in situ mechanical properties (e.g., hardness, elastic modulus, and volume fraction) of phases in high-alloy white iron measured by grid nanoindentation statistically, to reveal the contributions of individual phase properties to the global properties of the material. The in situ mechanical properties of phases measured by grid indentation were validated through targeted indentation. Gaussian and Weibull mixture models were used in analyzing the grid nanoindentation measurements to assess the goodness-of-fit of the indentation data. The nanohardness and indentation modulus measured by grid nanoindentation were directly correlated to the microstructural characteristics of the sample materials. The statistical analysis results were also compared with the mechanical properties and volume fractions obtained using targeted indentation and quantitative metallography based on microstructure analysis to validate the statistical results. The influences of heat treatment on the microstructure, hardness, and elastic modulus of individual phases in the material are also discussed.
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| 50. |
- Chen, Ling, et al.
(författare)
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Characterization of Microstructure and Mechanical Properties of High Chromium Cast Irons Using SEM and Nanoindentation
- 2015
-
Ingår i: Journal of Materials Engineering and Performance. - : Springer Science and Business Media LLC. - 1059-9495 .- 1544-1024. ; 24:1, s. 98-105
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of composition changes and heat treatment on the microstructure and mechanical properties of high-chromium white cast irons were studied in order to characterize possible improvements in product performance and machinability. Materials characterization was performed using nanoindentation, SEM, and EDS techniques. Present results show that changes in carbon and silicon contents as well as heat treatment strongly affect the mechanical properties and their variation in the material. In the as-cast condition, the sample with relatively lower carbon and silicon contents has an austenite-martensite matrix and is much harder than the sample with relatively higher carbon and silicon contents having more eutectic carbides in a bainite matrix. Annealing leads to softening of the materials relative to the as-cast condition, with the relatively higher carbon-silicon material being marginally harder due to the presence of more eutectic carbides. A similar trend is seen after the hardening treatment, and the presence of primary carbide can restrict the extent of hardening due to the loss of alloying elements from the matrix.
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