Session: 03-01-01: Advanced Manufacturing

Paper Number: 183429

183429 - Distinct Wear Mechanisms Involved When Machining Ti Alloys 

Titanium (Ti) alloys are prized in aerospace, medical, and automotive industries for their high strength-to-weight ratio, exceptional corrosion resistance, and biocompatibility. However, their unique material properties present a significant manufacturing challenge, as their machinability is distinctly poor compared to ferrous alloys. Current industrial practice demands conservative machining parameters to mitigate rapid tool wear and unpredictable tool fracture, the latter of which is often stochastic and difficult to predict.

This paper comprehensively reviews the research of the last decade to elucidate the dominant tool wear mechanisms when machining Ti alloys. Unlike ferrous alloys, which contain hard microstructural inclusions (e.g., cementite), Ti alloys lack major inclusions, prompting the fundamental question of what drives abrasive wear features, such as the characteristic scoring marks on the flank wear land.

The study highlights that crater wear is a complex interplay of abrasion and thermo-chemical wear (dissolution or diffusion). Experimental results utilizing advanced tool coatings demonstrate that as cutting speed increases, the influence of mechanical abrasion diminishes, and wear becomes increasingly dominated by diffusion-based mechanisms. Notably, while Ti alloys exhibit high solubility for dissolved tool elements, the diffusion of these elements into the Ti matrix is constrained. Understanding these distinct wear mechanisms is crucial for developing robust, high-performance tooling and optimizing machining strategies for Ti alloys.

Presenting Author: Patrick Kwon San Diego State University

Presenting Author Biography: Prof. Kwon is the chair in the department of mechanical engineering at San Diego State University after spending almost 30 years at Michigan State University. His area of research is machining and additive manufacturing.