Analysis of coating delamination under extreme contact loading

Abstract

This paper investigates the catastrophic failure due to wear of protective coatings when face-milling the Titanium alloy Ti-6242S in dry mode. The study employs a synergetic approach that teams finite element-based simulations to experimental observations in order examine the wear mechanisms for two groups of alloyed carbide inserts, (coated and uncoated). The results presented in this study pertain to cutting experiments performed at cutting speeds of 100–125 m/min and feed rates of 0.15–0.20 mm/tooth. Post experimental SEM micro-graphical analysis reveal that delamination is the primary wear mechanism for different cutting conditions, and that the major portion of delamination takes place at the very initial moments of cutting (first few seconds). Consequences of delamination on wear and the implications on the dry machining process of titanium and titanium based alloys are discussed.