Al_(2)O_(3)+TiO_(2)复合颗粒对激光熔覆Inconel 718基润滑涂层显微组织及高温磨损行为的影响研究  

Effects of Al_(2)O_(3)-TiO_(2) Composite Particles on the Microstructure and High-Temperature Wear Behavior of Laser Cladding Inconel 718-Based Lubricant Coatings

作　　者：张普 曹四龙 ZHANG Pu;CAO Silong(School of Materials Science and Engineering,Inner Mongolia University of Technology,Hohhot 010051,China)

机构地区：[1]内蒙古工业大学材料科学与工程学院,内蒙古呼和浩特010051

出　　处：《材料保护》2024年第6期8-19,共12页Materials Protection

基　　金：内蒙古自然科学基金(2022QN05025);内蒙古自治区直属高校基本科研业务费项(JY20220123)资助。

摘　　要：针对Inconel 718镍基合金易在宽温域条件下发生磨损失效的问题,选用2种不同含量Al_(2)O_(3)+TiO_(2)颗粒(10%,20%,质量分数)作为陶瓷增强相,利用激光熔覆技术制备了2种Inconel 718-MoS_(2)-Al_(2)O_(3)-TiO_(2)高温耐磨润滑复合涂层,系统地研究了复合涂层的微观组织、力学性能和摩擦学性能,以为其在摩擦学领域的应用提供数据支持。结果表明:复合涂层主要由γ-Ni固溶体、γ'-Ni_3(Ti, Al)金属间化合物、Ti_(3)O_(5)和Al_(2)O_(3)陶瓷增强相以及MoS_2润滑相共同组成。当TiO_(2)和Al_(2)O_(3)的含量达到20%时,更高含量的Ti_(3)O_(5)和Al_(2)O_(3)有利于涂层高的硬度和弹性模量,显微硬度最高可达455 HV_(0.3),然而会造成Ti_(3)O_(5)和Al_(2)O_(3)物相晶粒粗大,不利于弹性模量和抗塑性变形能力的提升。当摩擦温度为室温~200℃时,TiO_(2)和Al_(2)O_(3)含量为10%的复合涂层的摩擦系数和磨损率显著升高并达到了最大值,磨损机理主要为磨粒磨损和片层脱落;随着温度升高到400℃,涂层磨痕表面能够形成连续氧化膜促使磨损率显著降低。当温度达到600~800℃,2种复合涂层摩擦表面都能形成连续光滑的氧化膜起到润滑效应,使摩擦学性能得到显著改善,特别是磨损率相比于Inconel 718合金涂层降低1个数量级。当TiO_(2)和Al_(2)O_(3)含量达到20%时,复合涂层在中高温下有更优异的摩擦学性能。通过对比发现Inconel 718-MoS_(2)-Al_(2)O_(3)-TiO_(2)复合涂层相比于Inconel 718合金涂层在室温~800℃表现出更优异的摩擦学性能。To address the issue of wear failure in Inconel 718 nickel-based alloy under wide temperature conditions,two different contents of Al_(2)O_(3)+TiO_(2) particles(10%,20%,mass fraction)were selected as ceramic reinforcement phases.Two types of Inconel 718-MoS_(2)-Al_(2)O_(3)-TiO_(2) high-temperature wear-resistant lubricating composite coatings were prepared using laser cladding technology.The microstructure,mechanical properties and tribological behavior of the composite coatings were systematically investigated to provide data support for their application in the field of tribology.Results showed that the composite coatings were primarily composed of γ-Ni solid solution,γ'-Ni_(3)(Ti,Al)intermetallic compounds,Ti_(3)O_(5) and Al_(2)O_(3) ceramic reinforcement phases,as well as MoS_(2) lubricating phase.When the content of TiO_(2) and Al_(2)O_(3) reached 20%,higher levels of Ti_(3)O_(5) and Al_(2)O_(3) contributed to increased hardness and elastic modulus of the coatings,with a maximum microhardness of up to 455 HV_(0.3).However,this led to coarser grains of Ti_(3)O_(5) and Al_(2)O_(3) phases,which were unfavorable for enhancing the elastic modulus and resistance to plastic deformation.At friction temperatures ranging from room temperature to 200℃,the friction coefficient and wear rate of the composite coatings with 10%TiO_(2) and Al_(2)O_(3) content significantly increased,reaching maximum values.Wear mechanisms were mainly attributed to abrasive wear and delamination.As the temperature increased to 400℃,the formation of a continuous oxide film on the coating abrasion surface led to a significant reduction in wear rate.When the temperature reached 600~800℃,both types of composite coatings formed continuous smooth oxide films on the friction surfaces,exhibiting lubricating effects and significantly improving tribological performance,especially with a reduction in wear rate by one order of magnitude compared to Inconel 718 alloy coatings.When the content of TiO_(2) and Al_(2)O_(3) reached 20%,the composite c

关 键 词：激光熔覆 镍基复合涂层 高温耐磨损 宽温域自润滑 

分 类 号：TG174[金属学及工艺—金属表面处理]