中文摘要：

利用等离子喷焊工艺在热导率和化学成分不同的基体上制备高铝青铜喷焊层，研究喷焊层与基体间元素扩散对喷焊层显微组织及界面性能的影响。采用光学显微镜（OM）、XRD、SEM和EDS分析喷焊层表面组织、物相结构及其含量、界面显微结构和Fe、Al元素扩散。采用拉伸法测定喷焊层与基体结合强度。结果表明：45#钢基体中Fe元素向喷焊层扩散，界面处产生冶金焊合效果，结合强度达346.8 MPa，随着喷焊层中富Fe的K相含量的明显增加，表面硬度达301.3HV；ZQAl 9-4铝青铜基体的喷焊层中Al元素向基体扩散，随着界面处过渡层宽度的增加，结合强度显著提高，喷焊层中富Cu的α相含量增加，喷焊层表面硬度达272.7HV；T3紫铜基体的喷焊层中由于基体热导率高，喷焊层中Fe、Al元素向基体扩散量少，界面结合薄弱，结合强度最低。而其组织均匀细化，表面硬度显著提高。

英文摘要：

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 ZQAl 9-4 aluminum bronze substrate, and interface bonding strength is obviously improved with the increase of the width of the transition layer. The content of Cu-richαphase 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.