Inconel718合金激光熔覆Co/TiN复合涂层摩擦学及氧化行为

Tribologicaland oxidation behaviors of TiN/Co composite coatings on Inconel718 alloy by laser cladding

为了研究拓展Inconel718合金在高温环境下的应用,使用激光熔覆在其表面制备Co/TiN复合涂层,并结合XRD、SEM和EDS等分析方法,探究其在室温和600℃下的摩擦学行为及800℃下的抗氧化性能。结果表明:制备的涂层硬度相对基体有所提高,约为基体的1.3~1.4倍。另外,涂层中的物相主要为固溶体及金属间化合物。对涂层的摩擦学性能进行测试,当TiN添加量为4%(质量分数,下同)时,涂层的减摩性能最好;而添加量为6%时,涂层的耐磨性最好,磨损率最大可降低90.02%。此外,氧化实验表明:Co/TiN复合涂层具有一定的抗氧化性能,氧化速率为8.7634mg^(2)·cm^(-4)·h^(-1),与基体相差不大。由此说明该复合涂层在保留基体抗氧化性的同时,能够大幅降低高温下的磨损率,且磨损率随着TiN的增加而减小。通过磨损机理分析可知,在600℃下各涂层均发生氧化磨损,其表面氧化膜的产生一定程度上也有助于降低磨损率。

In order to study and expand the application of Inconel718 alloy in high temperature environment,Co/TiN composite coating was prepared on its surface by laser cladding.Meanwhile,the tribological behavior of the coatings at room temperature(RT)and 600℃,and the oxidation resistance at 800℃were investigated by XRD,SEM and EDS analysis,etc.The results show that the hardness of the composite coatings is 1.3-1.4 times higher than that of the substrate.The tribological properties of the coating are tested.When the TiN content is 4%(mass fraction,the same below),the anti-friction properties of the coating are the best.When 6%TiN added,the wear resistance of the coating is the best,and the wear rate can be reduced by 90.02%.In addition,the oxidation experiment shows that the Co/TiN composite coating has a certain oxidation resistance,and the oxidation rate is 8.7634 mg^(2)·cm^(-4)·h^(-1),which is not much different from the substrate.It shows that the composite coating can significantly reduce the wear rate at high temperature while retaining the oxidation resistance of the substrate,and the wear rate decreases with the increase of TiN.The wear mechanism analysis shows that the oxidation wear occurs on all coatings at 600℃,and the oxide film on the surface of the coatings also can reduces the wear rate at some extent.