Ni5Al/85Ni-15C复合涂层的性能及应用

Performance and application of Ni5Al/85Ni-15C composite coating

以Ni5Al合金粉末和85Ni-15C合金粉末为原料,采用大气等离子喷涂技术和火焰喷涂技术在镍基高温合金GH4169试片和零件表面制备Ni5Al/85Ni-15C复合涂层。对涂层的显微组织、物相组成、硬度和结合强度、微观形貌、车加工后的表面状态进行了分析。结果表明:涂层中润滑相石墨弥散分布于镍固溶体周围,镍熔滴包覆着石墨;黏结层组织较为均匀,氧化物少,无裂纹、界面分离、分层等现象产生。涂层表面洛氏硬度为66.62HR15Y,霍夫曼划痕硬度为9.5,黏结层的显微硬度为175 HV_(0.3),面层的显微硬度为70~170 HV_(0.3)。面层的结合强度为11.52 MPa,断裂形式属于“混合断裂”;层结合强度为23.86 MPa,断裂形式属于“脆性断裂”。涂层车加工后整体平整,呈现金属光泽,无宏观缺陷产生。

Using Ni5Al alloy powder and 85Ni-15C alloy powder as raw materials,Ni5Al/85Ni-15C composite coatings were prepared on the surfaces of nickel based high-temperature alloy GH4169 specimens and parts using atmospheric plasma spraying technology and flame spraying technology.The microstructure,phase composition,hardness and bonding strength,microstructure,and surface state after machining of the coating were analyzed.The results showed that the lubricating phase graphite was dispersed around the nickel solid solution in the coating,and the nickel droplets covered the graphite;The bond coating has a relatively uniform structure,with few oxides,and no cracks,interface separation,delamination,or other phenomena.The Rockwell hardness of the coating surface is 66.62 HR15Y,the Huffman scratch hardness is 9.5,the microhardness of the bond coating is 175 HV_(0.3),and the microhardness of the top coating is 70-170 HV_(0.3).The bonding strength of the top coating is 11.52 MPa,and the fracture mode belongs to"mixed fracture";The bonding strength of the bond coating is 23.86 MPa,and the fracture mode belongs to"brittle fracture".After processing,the coating car is overall smooth,presenting a metallic luster and no macroscopic defects.