| 1. |
- 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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| 2. |
- 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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| 3. |
- 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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| 4. |
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| 5. |
- 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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| 6. |
- 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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| 7. |
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| 8. |
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| 9. |
- 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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| 10. |
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