不同温度下TC21钛合金表面Cr-Al共渗层的耐磨性分析  

Tribological Behavior of Chromoaluminized Case of TC21 Titanium Alloy at Different Temperatures

作　　者：陈博文[1] 梁文萍[1] 缪强[1] 任蓓蕾[1] 夏金姣 丁铮[1] CHEN Bowen LIANG Wenping MIAO Qiang REN Beilei XIA Jinjiao DING Zheng(Collage of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100, Jiangsu China)

机构地区：[1]南京航空航天大学材料科学与技术学院,江苏南京211100

出　　处：《热处理》2017年第1期17-24,共8页Heat Treatment

基　　金：国家自然科学基金项目(51474131);江苏高校优势学科建设工程资助项目(PAPD)

摘　　要：为了提高TC21钛合金的耐磨性,采用双辉等离子渗金属技术对其进行了Cr-Al共渗。采用扫描电镜、能谱分析和X射线衍射分析了Cr-Al共渗层的微观组织形貌、物相组成等。采用硬度测试仪、纳米压入仪测定了Cr-Al共渗层的硬度和弹性模量。在20℃、300℃和500℃对基体及共渗层进行了球盘磨损试验,分析其磨损机制。结果表明,Cr-Al共渗层均匀致密,厚度为35μm,表面硬度达到950 HV0.1,约为基体的2.9倍;纳米硬度为7 506 MPa,弹性模量为506 GPa,分别是基体的2.4倍和3.3倍;TC21合金经Cr-Al共渗后,在以上三种温度下耐磨性均得到了提高。在20℃,TC21合金基体主要发生磨粒磨损、黏着磨损和氧化磨损,Cr-Al共渗层发生磨粒磨损和轻微的氧化磨损;在500℃,TC21合金基体的黏着磨损、氧化磨损及剥层磨损加剧,Cr-Al共渗层则处于氧化磨损与剥层磨损的动态平衡中。To improve the tribological behavior, TC21 titanium alloy was chromoaluminized by using a double glow plasma surface alloying technology. The microstructure and phase structure of the chromoaluminized case were investigated by means of scanning electron microscope, energy spectrum analysis and X-ray diffraction, and its hardness and elastic modulus were measured by hardness tester and nao-identing tester, respectively. Furthermore, the chromoaluminized case and the matrix were subjected to frictional wear tests at 20 ℃, 300 ℃ and 500 ℃ respectively, in order to reveal their wear mechanism. The results show that the chromoaluminized case is uniform and dense, exhibits a thickness of 35 μm and as high surface hardness as 950 HV0.1 which is 2.9 times as great as that of the matrix, as well as nano-indentation hardness of 7 506 MPa and elastic modulus of 506 GPa which are respectively 2.4 times and 3. 3 times those of the matrix. The chromoaluminized case has better wearability compared with the matrix at the three temperatures. In addition, wear mechanism of the matrix mainly is abrasion wear, adhesive wear and oxidation wear at 20 ℃, whereas wear mechanism of the case is abrasion wear and slight oxidation wear at the same temperature. The matrix offers relatively severe both adhesive wear and oxidation wear at 500 ℃, but the case offers oxidation wear and delamination wear which are in a dynamic equilibrium at the same temperature.

关 键 词：TC21钛合金 双辉等离子Cr-Al共渗 温度 耐磨性能 

分 类 号：TG156[金属学及工艺—热处理]