Kamiński Janusz, Sitek Ryszard, Adamczyk-Cieślak Bogusława, Kulikowski Krzysztof
Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507 Warsaw, Poland.
Materials (Basel). 2024 Sep 19;17(18):4592. doi: 10.3390/ma17184592.
This study presents a comparative analysis of the corrosion resistance of nitrided layers on conventional Grade 2 titanium alloy and those produced by direct metal laser sintering (DMLS). Low-temperature glow-discharge nitriding of the tested materials was carried out using conventional glow-discharge nitriding (so-called nitriding at the cathode potential-TiN/CP) and with the use of an "active screen" (nitriding at the plasma potential-TiN/PP). The TiN + TiN + Ti(N) layers were characterized by their microstructure, nanohardness profile distribution, surface topography, and corrosion resistance. The reduction in the cathodic sputtering phenomenon in the process using the active screen allowed the creation of surface layers that retained the topography of the base material. The parameters of the glow-discharge treatment led to grain growth in the printed substrates. This did not adversely affect corrosion resistance. The corrosion resistance of nitrided layers on the printed titanium alloy is only slightly lower than that of layers on the conventional Grade 2 alloy. Iron precipitates at grain boundaries facilitate increased nitrogen diffusion, resulting in reduced nitrogen concentration in the surface layer, slight changes in corrosion potential values, and increased nitrogen concentration in the Ti(N) diffusion layer.
本研究对传统2级钛合金上的渗氮层与直接金属激光烧结（DMLS）制备的渗氮层的耐腐蚀性进行了对比分析。采用传统辉光放电氮化（即所谓的阴极电位氮化-TiN/CP）以及使用“活性屏”（等离子体电位氮化-TiN/PP）对测试材料进行低温辉光放电氮化。通过微观结构、纳米硬度剖面分布、表面形貌和耐腐蚀性对TiN + TiN + Ti(N)层进行了表征。在使用活性屏的过程中，阴极溅射现象的减少使得能够形成保留基材形貌的表面层。辉光放电处理参数导致打印基材中晶粒生长。这并未对耐腐蚀性产生不利影响。打印钛合金上渗氮层的耐腐蚀性仅略低于传统2级合金上渗氮层的耐腐蚀性。晶界处的铁析出物促进了氮扩散增加，导致表面层氮浓度降低、腐蚀电位值略有变化以及Ti(N)扩散层中氮浓度增加。
