摘要
采用阴极弧蒸发技术沉积TiN涂层硬质合金,利用XRD、SEM和显微硬度计分析TiN涂层硬质合金氧化前后的物相组成、组织形貌和显微硬度的变化,并对其700℃和800℃抗氧化性能进行测试。研究结果表明:TiN涂层硬质合金氧化后出现边缘开裂,生成大量的氧化物;TiN涂层硬质合金的显微硬度在氧化过程中随着氧化温度的提高和氧化时间的延长不断降低。TiN涂层硬质合金氧化破损过程为局部不均匀氧化,O2通过氧化层或缺陷进入基体,造成基体氧化,体积发生膨胀,边缘处涂层应力集中,发生开裂,进而使基体发生氧化。
TiN coating was deposited on WC-8%（Ti,Ta,Nb）C-6%Co cemented carbide by cathodic arc-evaporation.The chemical composition,microstructure morphology and micro-hardness of the TiN coated cemented carbide were investigated by X-ray diffraction（XRD）,scanning-electron microscopy（SEM） and micro-hardness testing system.The oxidation tests were performed at 700 and 800 ℃ in air.The results show that cracks and lots of oxides appear at the border of the TiN coated cemented carbide after oxidizing 2 h in 700 and 800 ℃.The micro-hardness of TiN coated cemented decreases with the increasing of oxidation time and temperature during oxidation.The oxidation damage process of TiN coated cemented carbide is uneven oxidation,the O2 infiltrates into substrate through defects or oxide layer,and the volume of substrate swells,which results in border crack due to stress concentration of the coating,the substrate is oxidized finally.
出处
《粉末冶金材料科学与工程》
EI
2010年第4期356-361,共6页
Materials Science and Engineering of Powder Metallurgy
基金
高档数控机床与基础制造装备科技重大专项(2009ZX04012-021)
国家自然科学基金委员会创新研究群体科学基金资助项目(50721003)
关键词
涂层硬质合金
氧化
边缘开裂
显微硬度
coated cemented carbide
oxidation
border craze
micro-hardness
