Self-Peening of Titanium Alloys with Ti-Based Shot

摘要

Surface contamination from shot peening is a well accepted, but less often reported, consequence of shot-based surface modification processes. Residue from shot material on treated surfaces has been reported to decrease corrosion performance for Al, Fe and Mg alloys [1-3]. It would seem logical that using shot media with a similar chemical composition to the target material, i.e., self-peening, could be a possible solution to minimize surface contamination incurred by shot peening. Since Ti alloys are often used in corrosive environments (from chemical processing to biomedical implants), offering a self-peening solution for these alloys may be particularly helpful to assuage any fears about surface chemical contamination. This study shows a new process to harden Ti powder that can then be used as shot media for self-peening. The performance of the Ti-shot was evaluated in regards to the surface composition after shot peening and the residual stress evolved from shot peening, and then compared to peening with glass bead media.