(蘭州理工大學 甘肅省有色金屬新材料國家重點實驗室，蘭州 730050)
摘 要: 利用等離子噴焊工藝在熱導率和化學成分不同的基體上制備高鋁青銅噴焊層，研究噴焊層與基體間元素擴散對噴焊層顯微組織及界面性能的影響。采用光學顯微鏡(OM)、XRD、SEM和EDS分析噴焊層表面組織、物相結(jié)構(gòu)及其含量、界面顯微結(jié)構(gòu)和Fe、Al元素擴散。采用拉伸法測定噴焊層與基體結(jié)合強度。結(jié)果表明：45#鋼基體中Fe元素向噴焊層擴散，界面處產(chǎn)生冶金焊合效果，結(jié)合強度達346.8 MPa，隨著噴焊層中富Fe的K相含量的明顯增加，表面硬度達301.3HV；ZQAl9-4鋁青銅基體的噴焊層中Al元素向基體擴散，隨著界面處過渡層寬度的增加，結(jié)合強度顯著提高，噴焊層中富Cu的α相含量增加，噴焊層表面硬度達272.7HV；T3紫銅基體的噴焊層中由于基體熱導率高，噴焊層中Fe、Al元素向基體擴散量少，界面結(jié)合薄弱，結(jié)合強度最低。而其組織均勻細化，表面硬度顯著提高。
關(guān)鍵字: 高鋁青銅；噴焊層；界面擴散；顯微組織；界面結(jié)合強度
（Key Laboratory of Gansu Advanced Non-ferrous Metal Materials,
Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:High Al bronze coatings were fabricated on the substrate with different thermal conductivities and chemical components by plasma spray welding. The effects of element diffusion between the high Al bronze coatings and substrate on the microstructure and interface properties were studied. The morphologies, phase structures and phase element content of the spray welding coatings, and the interface morphologies and interface diffusion of Fe and Al were investigated by optical microscopy (OM), XRD, SEM and EDS. The interfacial bonding strength between the coatings and substrate was measured by tensile test. The results indicate that Fe in the 45# carbon steel substrate diffuses into the high Al bronze coating, a metallurgical welded interface forms, and interface bonding strength reaches 346.8 MPa. The content of Fe-rich K phase increases, and the hardness of the coating surface reaches 301.3HV. Al in the high Al coating diffuses onto ZQAl9-4 aluminum bronze substrate, and interface bonding strength is obviously improved with the increase of the width of the transition layer. The content of Cu-rich α phase increases, and surface hardness reaches 272.7HV. Due to the high thermal conductivity of T3 copper, little Fe and Al diffuse into T3 copper substrate, and interface bonding strength is the lowest. However, the microstructure of the coating is homogeneous and refined, and the surface hardness is dramatically improved.
Key words: high Al bronze; plasma spray coating; interface diffusion; microstructure; interface bonding strength
