TC4钛合金表面激光合金化Ti-Al-Nb涂层的研究  

Ti-Al-Nb Coating by Laser Alloying on TC4 Titanium Alloy

作　　者：戈晓岚[1] 仲奕颖 许晓静[1] 陶俊[1] 刘庆辉[1] 吴桂兰[1] 何星华[1] 

机构地区：[1]江苏大学,江苏镇江212013

出　　处：《稀有金属材料与工程》2017年第8期2266-2270,共5页Rare Metal Materials and Engineering

基　　金：江苏大学拔尖人才工程基金(1211110001);江苏省优势学科资助

摘　　要：以钛铝铌单质元素球磨混合粉末为原料,采用激光合金化技术在TC4钛合金表面成功制备出Ti-Al-Nb合金涂层。分析了涂层的物相组成、组织形貌及成分、显微硬度,并利用YG6球对磨来测试涂层在干摩擦条件下的摩擦磨损性能。结果表明:在激光功率P=1.8 k W,扫描速度V=5 mm/s,光斑直径D=2 mm下制备的涂层整体均匀致密、无裂纹,与TC4基体呈良好的冶金结合;涂层组织主要由Ti_3Al、AlNb_2、α-Ti 3种物相组成;Ti-Al-Nb涂层的显微硬度值沿层深方向呈平缓的梯度分布,平均硬度(HV)为5970 MPa,比TC4基体(3600 MPa)提高了66%;涂层平均摩擦系数为0.33,比TC4钛合金(0.45)降低了27%;涂层的磨损体积为0.044 mm3,耐磨性是钛合金基体(0.130 mm^3)的2.95倍。Ti-Al-Nb alloy coating was fabricated on the surface of TC4 titanium alloy by laser alloying using Ti, Al, Nb milled powders as the raw materials. The phase composition, microstructure and micro-hardness of the coating were investigated. The friction wear property of the coating was tested with the YG6 ball as counter-body under dry friction. Results show that with the laser power 1.8 k W, scanning speed 5 mm/s and spot diameter 2 mm, the prepared coating is uniform, dense and crack-free, and it has a good metallurgical combination with the TC4 substrate. The microstructure of the coating mainly consists of Ti3 Al, AlNb2 and α-Ti. The micro-hardness（HV） of the coating（5800~6300 MPa） is significantly higher than that of the TC4 matrix（3500~3600 MPa）. The friction coefficient of Ti-Al-Nb coating is reduced from 0.45 to 0.33 and the wear resistance is 2.95 times greater than that of the substrate.

关 键 词：TC4钛合金 激光合金化 复合涂层 显微组织 摩擦磨损性能 

分 类 号：TG174.4[金属学及工艺—金属表面处理]