TC4和TC11合金磨损性能的对比研究

A Comparison on the Wear Performance of TC4 and TC11 Alloys

采用MG-2000型高温磨损试验机对TC4和TC11合金在25和600℃进行磨损试验.利用SEM、EDS、XRD对两种钛合金的磨损表面及剖面的形貌、成分及结构进行对比观察与分析,利用HVS-1000型显微硬度计测试磨损表面至基材的硬度梯度分布.结果表明:TC4和TC11合金在25和600℃时磨损表面均形成了摩擦层.但在25℃时,摩擦层比较薄且分布不均匀,合金的磨损性能并未得到改善,因此两种钛合金的磨损率均随着载荷的增加而增加,磨损机制为黏着磨损和磨粒磨损;600℃时,摩擦层厚度增加,分布均匀且含有较多高硬度的摩擦氧化物,因此两种钛合金的磨损率较25℃时均有大幅度的减小,且TC11合金的磨损率低于TC4合金,磨损机制为氧化轻微磨损.可以认为,TC4和TC11合金在25℃时均具有较差的抗磨损性能,而在600℃时均具有非常优异的抗磨损性能.

Wear tests of TC4 and TC11 alloys were performed at 25 and 600 ℃ on a MG- 2000 type high temperature wear tester. The morphology,cross- section morphology,composition and structure of worn surfaces for these two titanium alloys were comparatively observed and analyzed with scanning electron microscopy,energy disperesive spectrum and X- ray diffraction. The hardness profile of the worn surface to the matrix was measured using an HVS- 1000 type digital microhardness tester. The results show that TC4 and TC11 alloys presented poor wear performance at 25 ℃ but excellent wear performance at 600 ℃. Tribo- layers on the worn surfaces of TC4 and TC11 alloys were obviously different at 25 and600 ℃. At 25 ℃,thin and uneven tribo- layer was observed and the wear performance of titanium alloys were not improved. In addition,the wear rate increased with an increase of load. The wear mechanisms were adhesive and abrasive wear. At 600 ℃,because of the thick and even tribo- layer containing high hardness tribo- oxides,wear rate was substantially lower than that at 25 ℃. And wear rate of TC11 alloy was lower than that of TC4 alloy. The wear mechanism were mild oxidation wear.