High Temperature Tribological Behavior of PVD Al_xCr_(1-X)N Coatings on Cemented Carbide and Steel Cutting Tools.
Syamala Rani Pulugurtha, Deepak G. Bhat
Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR, USA
Mariana H. Staia, Eli S. Puchi-Cabrera and Marlon Cruz
School of Metallurgy and Materials Science, Central University of Venezuela, Caracas, Venezuela
Abstract
The growing trend to improve component lifetimes coupled with the need to conserve resources is driving new technologies in fields such as tool and forming industries. CrAlN films have been recently reported to increase the thermal resistance in air due to the formation of complex aluminum and chromium oxides, which eventually suppress oxygen diffusion to the bulk. A commercial Al_xCr_(1-x)N coating (Balzers Alcrona) was deposited on M-2 steel and cemented tungsten carbide tool substrates, and tested for high-temperature wear behavior using a pin-on-disc tribometer against alumina counterface. The tests were performed in ambient air at room temperature, 200^oC, 400^oC and 600^oC, and the profiles of the wear tracks were measured using a laser profilometer. The wear tracks were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX) techniques. The results showed that at the temperatures of 400^oC and 600^o C, the coatings were worn through, irrespective of the nature of the substrate used.
Keywords: Al_xCr_(1-x)N, Cutting Tools, Wear, High Temperature Tribology.