工业纯钛TA2离子渗氮后的组织结构与真空摩擦磨损性能研究  

Microstructure and Vacuum Tribological Properties of Commercial Titanium TA2 Treated by Plasma Nitriding

作　　者：佘丁顺[1] 岳文[1] 付志强[1] 王成彪[1] 申灏[2] 刘家浚[3] 

机构地区：[1]中国地质大学(北京)国土资源部深部地质钻探技术重点实验室,北京100083 [2]中国铁道科学研究院金属及化学研究所,北京100081 [3]清华大学,北京100084

出　　处：《稀有金属材料与工程》2015年第1期133-139,共7页Rare Metal Materials and Engineering

基　　金：北京自然科学基金(3132023);国家自然科学基金(51275494);中央高校基本业务费(2012ZY51);清华大学摩擦学国家重点实验室开放基金(SKLTKF11B04)

摘　　要：为研究工业纯钛TA2经离子渗氮技术处理后的真空摩擦磨损性能,利用光学显微镜、白光三维形貌仪、X射线衍射仪和显微硬度计分别对渗氮前后材料的微观结构、表面形貌及表面粗糙度、相组成和硬度进行表征。采用真空摩擦磨损试验机对TA2渗氮前后的摩擦磨损性能测试后,使用白光三维形貌仪、扫描电镜及其附带能谱仪分析磨痕的表面形貌及磨痕表面的元素组成。结果表明:离子渗氮后,TA2表面形成的渗氮层主要由Ti N、Ti2N和α-Ti(N)等硬质相组成,厚度约为80μm,且表面HV硬度由1.40 GPa提升至12.60 GPa;离子渗氮处理使TA2在真空环境中的摩擦系数和磨损体积显著降低,从而有效减摩抗磨;然而在大气条件下,渗氮层的形成导致材料的摩擦系数和耐磨性均显著提高;此外,离子渗氮后材料的磨损机制也发生显著改变:在大气条件下,渗氮后样品的磨损机制由原始样品的磨料磨损、塑性形变及轻微粘着磨损共同作用转化为严重塑性形变、粘着磨损和材料转移,而在真空环境中,原始样品表面主要发生了粘着磨损、塑性形变同时伴有轻微的磨料磨损,而渗氮后材料磨损机制则为磨料磨损。To investigate vacuum tribological properties of commercial titanium TA2 treated by plasma nitriding, optical microscope（OM）, 3D profilometer, X-ray diffraction（XRD） and micro-hardness tester were used to characterize the microstructure, surface morphology, surface roughness, phase composition and micro-hardness of samples. Vacuum tribological properties of the original and the nitrided samples were tested by a vacuum tribometer, and then the morphology and composition of worn surface were investigated by scanning electron microscope（SEM） and energy dispersive X-ray spectroscopy（EDS）. The results show that a nitride layer consisting of hard phases TiN, Ti2N and α-Ti（N） is formed with a depth of 80 μm. Besides, surface HV hardness is evidently improved from 1.40 GPa to 12.60 GPa after plasma nitriding; meanwhile the surface roughness, friction coefficient and wear resistance of commercial titanium are observably enhanced in atmosphere. Nonetheless, friction coefficient of samples tested in vacuum is decreased, and a milder wear is performed. In addition, the wear mechanism changes due to the formation of nitrided layer. In atmosphere, the wear mechanism of the original samples is the co-action of abrasive wear, plastic deformation and slight adhesive wear; nonetheless, the wear mechanism of the nitrided samples is severe plastic deformation, adhesive wear and material transfer. However, in vacuum severe adhesion wear, plastic deformation and mild abrasive wear occur on the surface of the original samples, while the worn surface of the nitrided samples tested in vacuum exhibits a typical abrasive wear feature.

关 键 词：工业纯钛TA2 离子渗氮 组织结构 真空摩擦学 磨损 

分 类 号：TG156.82[金属学及工艺—热处理]