The effect of Al2O3, TiN and Ti (C,N) based CVD coatings on tool wear in machining metal matrix composites

The effect of Al2O3, TiN and Ti (C,N) based CVD coatings on tool wear in machining metal matrix composites containing 10 wt.% SiC particles produced by liquid metallurgy was investigated at different cutting conditions. In turning tests, various cutting speeds and two cutting tools having different chip breaker geometry were used at a constant feed rate and depth of cut. The results showed that the tool life decreased considerably with increasing particle size and cutting speed in machining the particle-reinforced composite. The wear performance of TiN-coated tool was considerably lower than that of Al2O3-coated tool in machining the composites with various particle sizes. Cutting speed was also found to be more effective in machining the composite. Moreover, it was observed that mild abrasive was the main responsible mechanism for wear of the tool. (C) 2003 Elsevier B.V. All rights reserved.