表面渗硼对新型β-钛合金耐腐蚀性能的影响  

Effect of Surface Boronizing on Corrosion Resistance of New β-Titanium Alloy

作　　者：王昊 张娇娇 冯晓飞 王鹤峰 WANG Hao;ZHANG Jiao-jiao;FENG Xiao-fei;WANG He-feng(College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学机械与运载工程学院,太原030024

出　　处：《表面技术》2020年第5期230-236,共7页Surface Technology

基　　金：国家自然科学基金(11172195,11702185)。

摘　　要：目的通过制备渗硼涂层,提高新型β-钛合金的耐腐蚀性能。方法采用固体粉末包埋法,在空气及氮气气氛中,选取不同的渗硼温度,在Ti-33Nb-4Sn(简称334钛合金)表面渗硼。对比分析涂层的表面、断面形貌,总结渗硼涂层的生长规律。利用电化学测试方法,测定334钛合金制备渗硼涂层前后,在3.5%NaCl溶液中的电化学腐蚀性能。结果在不同的制备条件下,都能在新型β-钛合金表面形成一层致密、连续的渗硼层。该涂层为双层结构,由致密的外涂层和针须状的过渡层组成。在相同气氛下制备的涂层,随着渗硼温度的升高,致密外涂层厚度增加。在氮气气氛下制备的涂层致密外涂层的厚度,大于同温度下在空气中制备的涂层。基体经过不同条件渗硼处理后,开路电位都明显提高。334钛合金基体的自腐蚀电位为0.6692 V,腐蚀电流密度为2.356μA/cm^2。在空气中经过900、950、1000℃温度渗硼后,自腐蚀电位分别为1.0993、0.7221、0.7639 V,腐蚀电流密度分别为3.377、2.274、1.584μA/cm^2。在氮气中经过900、950、1000℃温度渗硼后,自腐蚀电位分别为0.8617、0.6804、0.8143 V,腐蚀电流密度分别为1.358、1.445、1.525μA/cm^2。结论渗硼涂层可提高334钛合金的耐腐蚀性能,氮气气氛下制备涂层的耐腐蚀性能明显优于空气气氛。The paper aims to improve the corrosion resistance of new β-titanium by preparing boronizing coating. In this paper, the surface of Ti-33Nb-4Sn(334 titanium) was boronized in air and N2 atmosphere at different temperature by pack cementation. The surface morphology and cross-section morphology of the coating were compared and analyzed, and the growth rule of boronizing coating was summarized. The electrochemical test method was used to determine the electrochemical corrosion performance of 334 titanium alloy substrate and boronizing coating in 3.5%(mass fraction) NaCl solution. Under different preparation conditions, a dense and continuous boronizing coating can be formed on the surface of the 334 titanium alloy. The coating consists of a dense outer layer and a needle-like transition layer. For the coating prepared in the same atmosphere, the thickness of the dense outer coating increased with the increase of the boronizing temperature. The thickness of the dense outer coating prepared in N2 atmosphere was thicker than the coating prepared in air at the same temperature. After boronizing treatment under different conditions, the open circuit potential of the substrate increased. The self-corrosion potential of 334 titanium alloy was 0.6692 V and its corrosion current density was 2.356 μA/cm^2. After boronizing in the air at 900, 950, 1000 ℃, the self-corrosion potential was 1.0993, 0.7221, 0.7639 V, the corrosion current density was 3.377, 2.274, 1.584 μA/cm^2. After boronizing in N2 atmosphere at 900, 950, 1000 ℃, the corrosion potential was 0.8617, 0.6804, 0.8143 V, and the corrosion current densities was 1.358, 1.445, 1.525 μA/cm^2. The boronizing coating can improve the corrosion resistance of 334 titanium alloy. The coatings made in N2 atmosphere have better comprehensive corrosion resistance than that made in air.

关 键 词：β-钛合金 渗硼 改性涂层 电化学测试 固体包埋法 腐蚀 

分 类 号：TG174.4[金属学及工艺—金属表面处理]