原位生成TiC对TiC-Ni25复合涂层常温/高温耐磨性的影响  

Effect of in situ TiC Generation on the Ambient/High Temperature Wear Resistance of TiC-Ni25 Composite Coatings

作　　者：江国业 彭晨 Jiang Guoye;Peng chen(School of Aeronautical Engineering,Civil Aviation University of China,Tianjin 300300,China;School of Transportation Science and Engineering,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学航空工程学院,天津300300 [2]中国民航大学交通科学与工程学院,天津300300

出　　处：《激光与光电子学进展》2024年第5期328-340,共13页Laser & Optoelectronics Progress

基　　金：国家自然科学基金民航联合基金重点项目(U2033211)。

摘　　要：为了提高球墨铸铁的耐磨损性能,采用原位生成和直接添加TiC的方法激光熔覆制备TiC-Ni25金属复合涂层,研究不同Ti添加量对TiC-Ni25复合涂层微观组织、显微硬度以及25,200,400℃温度下的摩擦磨损性能的影响。结果表明:具有较强导热性和促石墨化的Ti元素减少了复合涂层与基体结合区莱氏体的生成;Ti作为强碳化物形成元素也促进了TiC的原位生成,TiC在涂层中起到细晶强化、晶间强化和弥散强化的综合作用,提高了涂层的耐磨性能,同时起到控制复合涂层气孔、裂纹缺陷的作用。添加Ti后原位生成TiC,TiC对涂层硬度的增强作用与富集Ti对涂层的增韧作用呈现互斥效应。5%Ti-10%TiC-Ni复合涂层的显微硬度较2%Ti-10%TiC-Ni和8%Ti-10%TiC-Ni复合涂层更高,而且该涂层在各环境温度下所表现出的摩擦磨损性能也更好,主要是因为形成了致密氧化膜,强化了对磨损区域的保护。200℃时各复合涂层的摩擦因数、磨损体积和磨损率均增大,这是由于粗糙氧化膜的形成降低了耐磨性能。复合涂层在25℃温度下的主要磨损机制为磨粒磨损和轻微黏着磨损,在200℃和400℃时主要是氧化磨损、疲劳磨损和黏着磨损。To improve the wear resistance of ductile iron,TiC-Ni25 metal composite coatings are prepared by laser fusion coating using in situ generation and direct TiC addition.The effects of different Ti additions on the microstructure,microhardness and friction and wear properties of TiC-Ni25 composite coatings at 25℃,200℃and 400℃are respectively investigated.The results show that Ti,which has strong thermal conductivity and promotes graphitization,reduces the generation of lysite in the bonding area between the composite coating and the matrix.And Ti,which is a strong carbide forming element,also promotes the in situ generation of TiC,which plays a role for combination of fine grain strengthening,intergranular strengthening and diffusion strengthening in the coating.The addition of Ti improves the wear resistance of the coating,controlls the porosity and cracks defects of the composite coating.Due to the competition between the hardness enhancement of TiC generated in situ and the toughening effect of enriched Ti,the microhardness of the 5%Ti-10%TiC-Ni composite coating is higher than that of 2%Ti-10%TiC-Ni and 8%Ti-10%TiC-Ni coatings.The friction and wear properties of the 5%Ti-10%TiC-Ni composite coating are excellent at above temperatures because of the formation of dense oxide film,which strengthens the protection of the wear area.The increases in friction coefficient,wear volume and wear rate of the composite coatings at 200℃are due to the formation of rough oxide film,which reduces the wear resistance.The main wear mechanisms of the composite coatings are abrasive wear and slight adhesive wear at 25℃,and oxidation wear,fatigue wear and adhesive wear at 200℃and 400℃.

关 键 词：激光熔覆 复合涂层 TIC 摩擦磨损 

分 类 号：TG174.4[金属学及工艺—金属表面处理]