Degree Type

Dissertation

Date of Award

2015

Degree Name

Doctor of Philosophy

Department

Mechanical Engineering

First Advisor

Xinwei Wang

Abstract

Diamond exhibits many attractive properties including extreme hardness, high thermal conductivity, high Young’s modulus, low coefficient of friction, low wear rate, biocompatibility and chemical inertness the Institutional Repository. Therefore, diamond tools have attracted number of applications in manufacturing of various microdevices and ductile machining of brittle materials. However, just because of these special features, manufacturing of diamond tools is very complex, time consuming and high cost. Laser shock wave induced freeform technique (SWIFT) can be considered as an innovative technique for manufacturing of diamond microtools that employing laser induced shock waves to mechanically sinter nanodiamond powders. Laser shocks can impart desirable dislocation structures and compressive residual stresses into material to improve the relative density and generate residual stress to enhance the fatigue strength. In this work, multiscale models based on laser-material interaction, high pressure sintering of nanodiamond powders and interface effects are utilized to explore the physics underlying this technique. Finite element simulation is applied to analyze the mechanical deformations induced by laser shock wave sintering. Scanning electron microscopy, optical profilometery, raman spectroscopy and micro-indentation are employed to characterize the microstructure evolution, phase transition, and hardness improvement. Tool wear test is carried out to investigate the product final performance.

Copyright Owner

Cheng Deng

Language

en

File Format

application/pdf

File Size

106 pages

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