SiO_2、Al_2O_3、ZrO_2对磨副材料对离子渗氮工业纯钛TA2磨损性能的影响

Effects of SiO_2,Al_2O_3 and ZrO_2 counter frictional materials on wear behaviors of plasma nitrided commercial titanium TA2

研究了离子渗氮处理工业纯钛TA2与硬质材料对磨的磨损性能。采用球盘摩擦磨损试验机评价摩擦学性能,选取了3种硬度的对磨副材料Si O2、Al2O3、Zr O2。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TA2的微观组织结构和硬度进行表征,并分析磨痕的表面形貌及元素组成。结果表明,渗氮后TA2表面生成了80μm厚的Ti N、Ti2N和α-Ti(N)硬质相渗氮层,表面硬度由140 HV提高至1260 HV,耐磨性能得到了提高。未处理样品的磨损机制主要是严重的黏着磨损、塑性形变和一定程度的磨粒磨损;渗氮样品的磨损机制主要为磨粒磨损,磨损率随对磨副材料硬度的升高而增大。

The tribological properties of plasma nitrided and untreated commercial titanium TA2 were evaluated by a ball-on-disk tribometer when sliding against SiO2,Al2O3 and ZrO2,respectively. The microstructure and microhardness of the TA2 were characterized by optical microscope,3D profilo-meter,X-ray diffraction( XRD) and microhardness tests. The morphology and composition of the worn surface after sliding test were investigated by scanning electron microscopy( SEM) and energy dispersive X-ray spectroscopy( EDS). The results show that a hard nitrided layer with a depth of 80 μm is formed,which consistes of hard phases TiN,Ti2N,and α-Ti( N). In addition,surface hardness is evidently increased from 140 HV to 1260 HV after plasma nitriding,and the wear resistance is greatly improved. The main wear mechanisms of the untreated TA2 are severe adhesion,plastic deformation and a certain degree of abrasion,when sliding against SiO2,Al2O3 and ZrO2,respectively. The main wear mechanism of nitrided TA2 is abrasion,while the wear rate increases with the increasing hardness of counter materials.