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- Rebeggiani, Sabina, 1980-, et al.
(författare)
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A Training Consortium to Explore and Exploit Surface Metrology
- 2014
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The importance of surface finish in all aspects of manufacturing influences economic considerations as well as environmental aspects and functionality. The ability to effective and efficient characterise surface topography is an important tool in the manufacturers arsenal which is often overlooked or underutilised. By providing a comprehensive, affordable training package, a gap in the industrial knowledge is filled giving manufacturers the ability to increase their competitive edge.
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| 4. |
- Rebeggiani, Sabina, 1980-
(författare)
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On Polishability of Tool Steels
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- One of the world’s fastest growing industries is the plastic industry. Today’s ever increasing demands of high quality products, shorter lead times and reduced costs push development and research forwards. Moulds for plastic injection moulding need to have a functional surface to meet demands on demoulding and wear properties, but also to produce the required final surface quality, which for ‘standard mould qualities’ of high gloss applications means nearly defect free, shiny and smooth mould surfaces with roughness levels in the nm-range.The aim of this thesis was to develop a metrology framework to quantitatively characterise these mould surfaces in order to gain better understanding of which defect structures are critical at injection moulding, and how these are correlated to material properties and operating conditions in surface preparation of tool steels. In practice this means to capture surface features of some few nm in height/depth up to some hundreds of microns in lateral dimension within insert areas of cm2 and larger. Experiments combining polishers’ experience with steel producers’ as well as non-contact areal texture examinations of surface topography were performed to overcome and link practical skills to academic ones.Based on areal surface metrology, defect classification and image analysis based surface characterisation, an evaluation procedure for polished tool steel surfaces was developed, initially tested and verified. The suggested method involves descriptions of relevant defect structures and acceptance levels for high gloss polished tool steels in the form of numerical parameter values based on interferometric measurements. It was also concluded that the cleanness of the steels was less important as long as it was kept within reasonable levels; the surface preparation strategy is a major factor influencing the mould surface quality e.g. it was found that a ‘several-step-strategy’ was favourable to avoid defect structures; not all ‘mirror-like’ mould surfaces had desirable topographies for injection moulding, therefore a well-defined mould surface assessment with numerical values describing mould surface quality is necessary to secure effective mould surfaces.
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- Rosén, Bengt-Göran, et al.
(författare)
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On in-vivo skin topography metrology and replication techniques
- 2005
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Ingår i: Journal of Physics, Conference Series. - Bristol : Institute of Physics Publishing (IOPP). - 1742-6588 .- 1742-6596. ; 13:1, s. 325-329
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Tidskriftsartikel (refereegranskat)abstract
- Human skin metrology is an area of growing interest for many disciplines both in research and for commercial purposes. Changes in the skin topography are an early stage diagnosis tool not only for diseases but also give indication of the response to medical and cosmetic treatment. This paper focuses on the evaluation of in vivo and in vitro methodologies for accurate measurements of skin and outlines the quantitative characterisation of the skin topography. The study shows the applicability of in-vivo skin topography characterisation and also the advantages and limitations compared to conventional replication techniques. Finally, aspects of stripe projection methodology and 3D characterisation are discussed as a background to the proposed methodology in this paper.
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- Thomas, T. R., et al.
(författare)
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Traceology, quantifying finishing machining and function : A tool and wear mark characterisation study
- 2009
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Ingår i: Proceedings of the 12th International Conference on Metrology and Properties of Engineering Surfaces. - Rzeszow, Poland : Rzeszow University of Technology. - 9788371995453 ; , s. 209-215
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Konferensbidrag (refereegranskat)abstract
- Traceology is defined as the study of wearmarks and its history in criminology and archaeology is briefly described. It is proposed that the concept of traceology can be extended to machined surfaces, particularly those produced by abrasive techniques. A taxonomy of wearmarks is outlined which would encompass both pits and scratches. Taxonomic implementations such as the morphology rose and the morphological tree are introduced. The general principles of traceology are illustrated by case studies from criminology, archaeology and abrasive machining processes.
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- Thomas, Tom R., et al.
(författare)
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Traceology, quantifying finishing machining and function : A tool and wear mark characterisation study
- 2011
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Ingår i: Wear. - Amsterdam : Elsevier. - 0043-1648 .- 1873-2577. ; 271:3-4, s. 553-558
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Tidskriftsartikel (refereegranskat)abstract
- Traceology is defined as the study of wear marks and its history in criminology and archaeology is briefly described. It is proposed that the concept of traceology can be extended to machined surfaces, particularly those produced by abrasive techniques. A taxonomy of wear marks is outlined which would encompass both pits and scratches. Taxonomic implementations such as the morphology rose and the morphological tree are introduced. The general principles of traceology are illustrated by case studies from criminology, archaeology and abrasive machining processes.
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- Xiao, Li
(författare)
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Gear tribology : friction and surface topography
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The quest for energy efficiency leads to the development of highly efficient power transmissions for vehicles. Gears are some of the most rugged and durable torque transmitters among machine elements. Friction between sliding surfaces at gear teeth is one major source of power loss. To increase efficiency and reduce damage accumulation in gears has always been a background motivation to this thesis. It focuses on the frictional performance of manufactured gear surfaces with emphasis on the effect of surface topography and the orientation of its lay.To achieve the goal of this work, a test rig was designed and constructed. The rig makes it possible to examine gear tooth friction on double crowned rollers. Five alternative gear-finishing processes are implemented in roller surface preparation. They comprise grinding, shotpeening, phosphating, chemical deburring and DLC coating. Theoretically, a friction model is suggested which helps to explain some of the testing results. Advanced surface metrology techniques and statistical tools are implemented in identifying surface features that influence friction.The result demonstrates that surface topography is a significant factor affecting the lubricated frictional behaviour. For ground-finishing, the smoother the surfaces are finished, the lower friction coefficient they show. Chemical deburring and DLC coating as well as certain degrees of phosphating provide minimum friction coefficient and improved load carrying capacity, which are competitive to fine-ground finishing. Properly designed lay combinations of meshing gear surfaces can minimise friction and improve gear transmission efficiency. Theoretically, the friction coefficient can be explained by means of a combination of the slide-to-roll ratio and the real mean contact pressure within the range of loads considered in this thesis. Finally, features that correlate surface topography to friction are identified.
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