TiN和TiAlN涂层硬质合金的氧化和切削性能

Oxidation and cutting properties of TiN and TiAlN coated cemented carbide

采用阴极弧蒸发涂层工艺在硬质合金基体上分别沉积TiN和TiAlN涂层。利用XRD、SEM和显微硬度计分析2种涂层硬质合金氧化前后的物相组成、组织形貌和显微硬度,并对2种涂层硬质合金刀片进行切削性能测试。研究结果表明:2种涂层硬质合金在不同温度氧化一定时间后出现边缘开裂,基体氧化物鼓出。TiAlN涂层硬质合金抗氧化性能优于TiN涂层硬质合金。2种涂层硬质合金的显微硬度随着氧化时间增加而减小。由于TiAlN涂层硬质合金具有良好的抗氧化性,所以随着切削速度提高,表现出更好的切削性能。

The oxidation resistance of coated cemented carbides and the effect of which on cutting properties were studied.TiN and TiAlN coatings were deposited onto WC-8 %（Ti,Ta,Nb） C-6%Co cemented carbides by cathodic arc-evaporation.The micro-structure,morphology and micro-hardness of the coated cemented carbides were investigated using X-ray diffraction,scanning-electron microscopy and micro hardness testing system.The cutting test was performed at 160 m/min and 280 m/min.It is found that there are lots of oxides in the border of the TiN and TiiAlN coated cemented carbide after being oxidized two hours at 700 and 800 ℃.However,the border craze of TiAlN coated cemented carbide is later than that of TiN coated cemented carbide.Micro hardness of the TiN and TiAlN coated cemented carbide decreases as oxidation time increases.The cutting property of TiAlN is more obvious with the increase of the cutting speed,because of its better oxidation resistance.