Modelling of laser assisted machining of titanium alloys

Xi, Yao (2014). Modelling of laser assisted machining of titanium alloys PhD Thesis, School of Mechanical and Mining Engineering, The University of Queensland.

       
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Author Xi, Yao
Thesis Title Modelling of laser assisted machining of titanium alloys
School, Centre or Institute School of Mechanical and Mining Engineering
Institution The University of Queensland
Publication date 2014
Thesis type PhD Thesis
Supervisor Matthew Dargusch
Gui Wang
Shoujin Sun
Total pages 111
Total colour pages 21
Total black and white pages 90
Language eng
Subjects 0910 Manufacturing Engineering
0912 Materials Engineering
0913 Mechanical Engineering
Formatted abstract
Titanium alloys have become very attractive materials for a wide range of applications due to their superior properties such as high strength to weight ratio, exceptional corrosion resistance and low Young’s modulus. The usage of titanium alloys is, however, strongly limited by their higher machining cost comparing with other materials.

Titanium alloys are known as difficult to machine materials. In order to meet the increasing demand for machined titanium alloy components, a great amount of effort has been directed by researchers into developing advanced machining technologies to improve the machinability of titanium alloys in order to improve the productivity. Laser assisted machining (LAM) is an advanced machining technique which has been developed based on the idea of reducing the material strength by locally heating the workpiece using laser radiation before the cutting tool removes the unwanted material. This process has been applied in many machining of titanium alloys studies and has been proved effective in terms of improving the machinability of titanium alloys.

Many experimental studies have been conducted by researchers to study the laser assisted machining process. However, it is very difficult to gather all the important information associated with this process through experiments. Thus it is difficult to understand some mechanisms behind the machining process solely by experimental studies, and experimental studies are resource intensive and expensive. Modelling and simulation are powerful tools that can be used to predict the outcomes of laser assisted machining. Therefore, in order to further understand and optimize this process, simulation studies of this process need to be performed. And the purpose of this research is to apply the finite element method to study the process of laser assisted machining of titanium alloys.

The traditional finite element method and the smoothed-particle hydrodynamics (SPH) method have been used to simulate thermally assisted machining and laser assisted machining, which is a new research area that was not previously investigated by other researchers at the time this project commenced. All the simulations have been validated through comparisons between the experimental results and the simulation predictions. A deep understanding of the chip formation mechanism during machining of titanium alloys has been developed during this research using both methods. Furthermore, for the first time the SPH machining model was used to relate the chip formation process and the cutting force vibration.

Several papers based on the findings of this project have been published by the author during the candidature which have contributed to the understanding of several important mechanisms associated with laser assisted machining. The machining models developed in this research could be ii used in future to conduct parametric studies on the laser assisted machining processes to provide guidelines on parameter selections. Furthermore, the machining models developed in this research may aid the future development of tool wear simulations which could help researchers and engineers understand the tool wear mechanisms during machining and provide guidelines to cutting tool selection, as well as cutting tool design in industry.
Keyword modelling
finite element
smoothed particle hydrodynamics
Laser assisted machining
Titanium alloys
Chip formation
Cutting Force

 
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Created: Tue, 23 Sep 2014, 09:23:14 EST by Yao Xi on behalf of Scholarly Communication and Digitisation Service