Ni_3Al型金属间化合物涂层中原位自生的M_7C_3型碳化物及涂层耐磨性研究  

Study on In-situ Synthesized M_7C_3 Carbide and Wear Resistance of Ni_3Al Type Intermetallic Compound Coating

作　　者：袁建鹏[1,2,3] 于月光 王玉[3,4] 

机构地区：[1]北京矿冶研究总院,北京100160 [2]东北大学,沈阳110819 [3]北京市工业部件表面强化与修复工程技术研究中心,北京102206 [4]特种涂层材料与技术北京市重点实验室,北京102206

出　　处：《热喷涂技术》2017年第4期13-23,共11页Thermal Spray Technology

基　　金：北京市科技计划课题(Z171100002217061);国家国际科技合作专项(2015DFA50970)

摘　　要：本文针对工业高温高耐磨的防护需求,研究一种原位自生Cr_xC_y碳化物增强Ni_3Al金属间化合物涂层,替代现有的Ni Cr-Cr_3C_2涂层。研究中采用真空雾化工艺制备了碳化物体积含量70%的一种原位自生碳化物的Ni_3Al型金属间化合物粉末,通过HVOF喷涂工艺制备涂层。借助扫描电镜和X射线衍射等手段,研究粉末与涂层的显微组织、相成分及碳化物分布形貌。结果表明,粉末和涂层中的碳含量均与设计保持一致;粉末以及涂层中的显微组织均主要由(Ni,Cr)_3Al+M_7C_3型碳化物相组成,且粉末和涂层中的两相比例基本一致;其中弥散分布的原位自生M_7C_3型碳化物呈条片状,X射线衍射配合电子能谱分析显示该碳化物为(Cr,Al)_7C_3;测试并比较了研制涂层与商用Cr_3C_2-Ni Cr涂层的硬度和滑动摩擦磨损性能,当温度升高到700℃,研制涂层的显微硬度几乎没有变化;含有原位自生的M_7C_3型碳化物的Ni_3Al型金属间化合物涂层拥有比Cr_3C_2-Ni Cr涂层更低更稳定的摩擦系数、更好的磨损抗力以及与对磨副更佳的相容性,尤其高温耐磨性表现优异;研制涂层中片状条状M_7C_3型碳化物颗粒有效阻碍磨粒的显微切削运动,对摩擦副形成了很好的保护作用,显著改善了耐磨性。该涂层在高温对磨条件下具有很好的潜在应用价值。In order to meet the requirement of high temperature and high wear resistance, an in-situ CrxCy carbide reinforced Ni3Al intermetallic compound coating was studied to replace the NiCr-Cr3C2 coating. The powder , in which the carbide was in-situ synthesized, was ？rstly prepared by vacuum gas atomization, then it was subjected to high velocity oxy-fuel（HVOF） spraying to deposited coating.The microstructures,element composition, and the phase composition of the powder, as well as the sprayed coating were analyzed by SEM and XRD. The results showed that the phases of the sprayed coating were also mainly the M7C3 and the Cr doped Ni3Al, and the ratio of them was almost similar to it in the powder. Among them, the dispersed in situ M7C3 type carbide formed into strips, which was proved to be （Cr,Al）7C3 by X ray diffraction and electron energy spectrum analysis. In addition, The hardness and sliding wear performance of the sprayed coating was also tested and compared to a commercial Cr3C2-NiCr coating. When the temprature rised to 700℃, the microhardness of the coating was almost no changed.The coating was showed the improved wear resisrance, lower friction coef？cient and better compatibility to contourpart than Cr3C2-NiCr coating.The strip shape M7C3 carbide particles in the coating effectively prevent the micro cutting movement of the abrasive particles, and the friction pairs were well protected .The wear resistance was improved remarkably.The NACC coating showed its potential application at the high temprature.

关 键 词：NI3AL金属间化合物 高温耐磨涂层 原位自生碳化物 高温摩擦磨损 

分 类 号：TG174.4[金属学及工艺—金属表面处理]