Initial wear of cutting coated tools while machining TiMMC

This research investigates the early stages of wear in PVD-coated carbide tools during the machining of titanium metal matrix composites (TiMMCs) and aims to establish a correlation between initial wear signals and eventual tool failure. A combination of direct characterization techniques including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and focused ion beam (FIB) along with indirect monitoring methods such as cutting force and vibration signal analysis, was employed. Fractal analysis was applied to the recorded signals to identify wear transition points. Initial wear manifestations, such as coating delamination, material adhesion, and microcracking, were found to progressively develop into more severe wear mechanisms like diffusion, deep cracking, and edge chipping. These wear transitions were successfully correlated with irregular signal patterns, particularly through changes in fractal dimensions. The findings demonstrate that early wear indicators can reliably predict subsequent tool failure. By establishing a link between early-stage wear mechanisms and final failure modes, this study enhances the understanding of tool degradation in TiMMC machining. The gained insights contribute to the development of more effective wear monitoring systems, supporting increased efficiency and reliability in industrial machining operations.

Mots clés

• Titanium metal matrix composite
• Machining
• Turning
• Tool wear