多层涂层的抗氧化性能
(1. 中南大学 材料科学与工程学院，长沙 410083；
2. 株洲钻石切削刀具股份公司，株洲 412007)
摘 要: 对化学气相沉积(CVD)法制备的硬质合金TiN/TiCN/Al2O3/TiN多层涂层试样在600~950 ℃温度范围内进行了氧化质量增加试验，采用X射线衍射(XRD)和扫描电子显微镜(SEM)分析试样氧化前后相组成及微观组织。结果表明：复合涂层最外层为α-Al2O3时，涂层具有最佳的抗氧化能力；增加TiN/TiCN/κ-Al2O3/TiN复合涂层中TiCN和κ-Al2O3的厚度能大大提高涂层高温抗氧化性。TiN和TiCN涂层经600 ℃以上氧化后，产物均为金红石结构的TiO2，氧化后TiN/TiCN间的界面消失；经900 ℃以上氧化时，κ-Al2O3转变为α-Al2O3。
关键字: 硬质合金；化学气相沉积多层涂层；抗氧化性
coatings on cemented carbide by chemical vapor deposition
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Zhuzhou Cemented Cutting Tools Co., Ltd., Zhuzhou 412007, China）
Abstract:The oxidation mass gain test at the temperature range of 650−950 ℃ in different times were carried out on the cemented carbide coated by multilayer TiN/TiCN/Al2O3/TiN coating prepared by chemical vapor deposition (CVD) method. The phase component and microstructure of coating samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that, when the outset layer is α-Al2O3, the sample exhibits excellent oxidation resistance. The oxidation resistance of TiN/TiCN/κ-Al2O3/TiN multilayer coating sample is improved with the increase of the thickness of TiCN and κ-Al2O3. The oxidation product of TiN and TiCN layer is rutile TiO2 when the temperature is higher than 600 ℃, and the interface of TiN/TiCN disappears. The κ-Al2O3 transforms to α-Al2O3 when the oxidation temperature is above 900 ℃.
Key words: tungsten carbide; chemical vapor deposition multilayer coatings; oxidation resistance
