Application of Surface Severe Plastic Deformation to α+β and β Titanium Alloys for Microstructure Modification

2019-10-17T18:03:24Z (GMT) by David A Brice
This thesis provides an in depth look at the application of Shot peening to three alloys that cover a wide range of stabilizer compositions (Ti-64, Ti-5553 and Ti21S). Here the effects of Shot peening on the material were studied by characterizing the changes to subsurface microstructres in a variety of starting microstructures across all alloys studied. the study also compared the evolution of residual stress across all conditions and its effect on precipitation during post shot peening heat treatments.
Additionally, the study developed a novel shot peening media providing proof of concept for the idea of self-peening a material. This being the practice of peening the target material with the same material as media. Here the production of hardened Ti media was achieved to then self peen titanium alloys. the results from conventional and self-peened samples are compared in terms of corrosion resistance, surface hardening, surface roughness, and residual stress evolution.