钛合金表面百微米级Ti/TiN多层复合涂层性能研究

Properties of Hundred-Micron Ti/TiN Multilayer Composite Coating on Titanium Alloy

目的提高TiN硬质涂层的厚度及各项力学性能。方法采用等离子增强PVD技术在钛合金(TC4)基体表面制备多层复合Ti/TiN涂层,对涂层进行扫描电镜(SEM)分析,采用划痕法表征涂层的结合强度,用维氏显微硬度计测试涂层的显微硬度,利用销盘式摩擦磨损试验仪评价涂层的摩擦磨损性能。结果制备的多层复合Ti/TiN涂层厚度最高可达100μm,且未发生剥落等失效,结合强度相对于单层TiN提高了近3倍。由于Ti、TiN的多层复合调制作用,制备的Ti/TiN显微硬度测试表明复合涂层的显微硬度高达2700 HV0.025,同时,涂层在原有耐磨性能优良的基础上具备自润滑减摩作用,经过近20 000 m的磨损测试,复合涂层的摩擦系数低至0.25左右,且未完全失效。结论多层复合结构能够有效提高TiN硬质涂层的厚度,制备的Ti/TiN多层复合涂层的各项力学性能显著提高。

The work aims to improve thickness and various mechanical properties of TiN hard coating.Ti/TiN multilayer composite coatings were prepared by virtue of plasma enhanced PVD technology on the surface of Ti alloy（TC4） substrate.Microstructure of Ti/TiN coating was analyzed by using the scanning electron microscope（SEM）.The bonding strength was characterized by means of scratch test,micro hardness was determined by Vickers and friction-wear resistance was evaluated by using ball-on-disk abrasion apparatus.The Ti/TiN multilayer composite coating prepared was 100 μm thick,free from such failures spalling.Its bonding strength was nearly three times than that of the monolayer TiN coating.Because of complex modulation of Ti and TiN multilayers,the micro hardness was up to 2700HV0.025.Meanwhile,the coating showed excellent self-lubricant and antiwear effects in addition to original favorable wear resistance.The friction coefficient of composite coating was about 0.25 after nearly 20 000 m of wear test without complete failure.The thickness of the hard coating can be improved by the multilayer composite structure and various mechanical properties of Ti/TiN multilayer composite coating are also enhanced remarkably.