Study of the friction and wear behaviour of a coated cutting tool with different surface topologies
Author(s)
Dechjarern, Surangsee
Type
Thesis
Abstract
The main objective of this work was to investigate the effect of a wide range of surface roughness on coated tool performances and the possibility of using this study to improve the tool life. Tool wear is greatly affected by the tribological conditions at the tool/chip interface. The knowledge of the effect of surface roughness on tribological factors is required. The examination of the tribology behaviour of different surface roughnesses has been carried out in parallel with machining experiments. Numerical studies of machining using multi-scale models have also been investigated to enhance the optimising process further. Tool surfaces were roughened by electro-discharge machining (EDM) and the experimental studies suggested that EDM surfaces can be regarded as possessing Gaussian height distribution and can be represented by two surface parameters. The relationship between the surface characters with the product of the EDM parameters, Pe wore formulated. The EDM was found to be capable of producing a consistent, surface pattern. Friction tests of EDM uncoated and coated surfaces were then conducted using a modified pin-on-cylinder technique. The results allowed the range of surface roughness, where friction might, be minimized, to be identified. The mechanism of friction for both uncoated and coated rough surface contact, were analysed. The possible explanation of the minimum friction was presented via the effect of third-body abrasion using the ratio of the amount of wear and t he valley volume, Vw/G in addition to adhesion and ploughing components. A multi-scale analysis of metal cutting process has been successfully developed using the results from the friction tests. Macroscale finite element models of the machining process, which included the effect of strain hardening and temperature softening, has been constructed to investigate the effect of friction on cutting performance.
Version
Open Access
Date Awarded
2002
Advisor
Hibberd, Dr. R.
Busso, Dr. E.
Publisher Department
Department of Mechanical Engineering
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)