Wear performance of CAP-titanium nitride-coated high-speed steel in different dry sliding conditions

Load and speed are the most important sliding-wear parameters for coated tools used against counter materials but have been rarely discussed, particularly the popular CAP-TiN-coated tool. This study presents a wear test to profile the tribobehavior of a CAP-TiN-coated steel tool contacting with chromium steel as a function of load and speed. Wear-loss and friction-coefficient measurements were assessed to evaluate the sliding-wear resistance, and scanning electron microscopy and optical microscopy were used to identify wear modes. Experimental results show that the wear modes observed were polishing wear and mass transfer in low wear-load conditions of less than 39.2 N, while low stress-abrasion wear, macroparticle drop-off, Brinelling and mass transfer were found in high wear-load conditions ranging from 39.2 to 88.2 N. Only mass-transfer and macroparticle drop-off wear modes were found at high sliding speeds. If a low wear-load was employed independent of the sliding speed (up to 37 m min(-1) in this case) it had a minor effect on wear loss because the detrimental wear modes such as low stress abrasion and Brinelling do not occur. This study reveals the wear-immune region of the CAP-TiN-coated tool. Macroparticles, which are usually thought to reduce wear life, do not affect the wear performance at all in this dry sliding contact wear test. (C) 1997 Elsevier Science S.A.