载荷对铬-铝共渗层摩擦学性能的影响

Effect of Load on Tribological Property of Chromoaluminized Case of TC21 Titanium Alloy

为了提高TC21钛合金的摩擦学性能,采用双辉等离子渗金属技术对其进行了铬-铝共渗。采用SEM和EDS分析了渗层的显微组织和成分,并测定了硬度。在室温下,采用GCr15钢球作摩擦副,研究了330 g、530 g和730 g载荷下渗层和基体的摩擦性能及其磨损机制。结果表明,铬-铝共渗层的厚度约为35μm,平均硬度为1 100 HV0.1,约为基体的4倍。在3种试验载荷下,渗层的摩擦因数和比磨损率均比基体的低。在重载荷下,TC21钛合金基体的磨损机制为磨粒磨损、黏着磨损和氧化磨损,而共渗层则是以磨粒磨损和氧化磨损为主。

TC21 titanium alloy was chromoaluninized by a double-glow plasma surface alloying technology to enhance its tribological property. The chromoaluminized case was subjected to microstructure survey and composition analysis by SEM and EDS, and to hardness measurements. The frictional behavior and wear mechanism of both the case and the substrate were investigated by using GCr15 steel ball as friction pair under different loads of 330 g, 530 g and 730 g at room temperature. The results indicated that the case was as thick as about 35 μm, and possessed of mean hardness of 1 100 HV0.1 which was 4 times as great as that of the substrate. Both friction coefficient and specific wear rate of the case were lower than those of the substrate under the three test loads. The primary wear mechanism was abrasion wear, adhesive wear and oxidation wear for the chromoalumiuized case, and abrasion wear and oxidation wear for the TC21 alloy substrate, under heavy load.