摘要:
Ti6Al4V合金经800℃、1 h和900℃、15 min热氧化后,分别进行850℃、20 h真空扩散,并将900℃、15 min热氧化+850℃、20 h真空扩散后的试样在25℃和400℃下进行磨损试验,比较真空扩散后的显微硬度分布及处理前后的磨损量,通过XRD、SEM、EDS等分析手段对氧化、氧化/扩散及磨损后的结构和形貌进行测试分析。结果表明:Ti6Al4V合金经热氧化后,表面形成钛氧化物,再经真空扩散后,TiO2发生了分解,在表层和基体间形成了氧扩散层,增加了两者间的结合力,产生了硬化效应,同时形成一定数量的Al3Ti,在不同温度和载荷下,磨损量均比未处理试样的小;经900℃、15 min热氧化+850℃、20 h真空扩散后的Ti6Al4V合金,耐磨性可得以显著提高。
Abstract:
Ti6Al4V alloy was processed with thermal oxidation at 800℃ for 1 h or at 900℃ for 15 min, then processed with vacuum diffusion at 850℃ for 20 h.At 25℃ and 400℃,dry sliding wear tests were performed for the alloy that underwent thermal oxidation at 900℃ for 15 min and vacuum diffusion at 850℃ for 20 h.A comparative study on microhardness distributions of the samples after vacuum diffusion and weight losses of the samples with or without processing was carried out.Microstructures and morphologies of the samples after oxidation or oxidation/diffusion and wear tests were analyzed by XRD, SEM,and EDS etc.The results show that titanium oxide forms on the surface after thermal oxidation, then TiO2decomposes after vacuum diffusion.Between the surface oxide layer and the substrate,an oxygen diffusion layer generates and enhances their binding force,exhibiting a hardening effect.At the same time,some Al3Ti appears.Under different load or temperature,the weight losses of the samples after oxidation/vacuum diffusion are much smaller than those of the samples without processing.Therefore,it can be concluded that the wear resistance of Ti6Al4V alloy after thermal oxidation at 900℃ for 15 min and vacuum diffusion at 850℃ for 20 h is significantly improved.
点击查看大图
下载:
