Preparation Of TiAlN Coated Carbide Tool And Its Cutting Performance

Technical requirements of cutting tools are increasing with the rapid development of metal-cutting processes. The emergence of coated cutting tools had achieved a comprehensive modification of traditional tools, which also effectively improved the processing efficiency and precision, extended the tool life, and also reduced the production cost. Therefore, the preparation of high-performance coated cutting tool is particularly important. In this dissertation, pulse biased arc ion plating method was used to prepare the TiALN coated cemented carbide cutting tool on YT14.Single-factor test was used to analyze the influence of substrate negative bias, pulse bias duty ratio, arc current, nitrogen partial pressure and deposition temperature on coating thickness, surface morphology, nano-hardness and bonding strength.The optimized process parameters for TiAlN coated cutting tool were as follows:negative bias-50V, duty ratio 50%, arc current 95 A, nitrogen partial pressure 0.8Pa, deposition temperature 200℃. Composition and properties of TiAlN coated cutting tool were as follows:the coating composition was Ti0.52Al0.48N, the thickness was 3.1μm, the roughness was 0.1Oμm, the nano-hardness was 34.0GPa, the elastic modulus was 453.7Gpa and the bonding force was 58.9N.The effect of normal load and sliding speed on friction and wear properties of TiAlN coated cutting tool was researched. The results indicated that the wear scar width increased with the increasing of normal load, while the friction coefficient decreased. The wear scar width decreased with the increasing of the sliding speed, while the friction coefficient increased at first and then decreased. The main wear mechanisms of TiAlN coated cutting tool were abrasive wear, oxidation wear and adhesive wear in the friction and wear tests.When it came to the machining of hardened alloy 40Cr, the tool life of TiAlN is 1.8 times,2 times,2.3 times of YT14 respectively at three different cutting speeds (120m/min, 180m/min,240m/min), when keeping/=0.1mm/r, ap=0.2mm unchanged. The main wear mode was flank wear, and the main wear mechanisms were adhesive wear and abrasive wear.When it came to the machining of austenitic stainless steel 1Cr18Ni9Ti, the tool life of TiAlN is 2.5 times,2.7 times,2 times of YT14 respectively at three different cutting speeds (120m/min,180m/min,240m/min), when keeping/=0.1mm/r, ap=0.2mm unchanged. The main wear modes were rake wear, flank wear and tipping, and the wear mechanism was adhesive wear. Tipping became more serious with the increasing of cutting speed.