送粉激光堆焊梯度功能材料

Laser deposited welding of functional gradient materials with powder feeding

关键词:  激光堆焊  梯度功能  组织性能  修复

Key words:  laser deposited welding  functional gradient  microstructure and properties  repairing

摘要:

采用同步送粉的方法进行了316L不锈钢和铁基合金粉末的激光堆焊。通过显微组织观察、SEM电镜扫描、拉伸试验、磨损试验和EDAX能谱分析等手段对激光堆焊层组织性能以及成分进行了分析和测试。两种堆焊材料的梯度功能组合使得不同堆焊部位可以满足不同的工艺和性能要求。激光堆焊层和基体呈冶金结合、稀释率小,堆焊组织细小、致密、无裂纹、气孔等缺陷,底层试样抗拉强度和伸长率达到752.4 MPa和41.05%,表层材料磨损性能大大超过基体材料。送粉激光堆焊可以实现材料与性能的优化匹配,为金属零件的梯度功能修复和复杂零件的成形提供了一条有效途径。

Abstract:

Laser deposited welding of stainless steel and iron-based alloy was carried out with synchronized powder feeding method.The microstructure,properties and composition of the deposited layer were thoroughly analyzed and tested by means of microstructural observation,SEM scanning,tensile strength testing,wearing and EDAX analysis.Different process and property requirements at different deposited position can be satisfied with functionally gradient combination of different welding materials.The deposited welding layer presents a metallurgical bonding with the substrate,and the dilution is quite small.The microstructure obtained is fine,compact,and free of cracking and porosity.The tensile strength of the samples at the bottom of the deposited layers reaches 752.4 MPa,and the elongation 41.05%.The wearing resistance of the surface layer has greatly surpassed that of the substrate.The optimized matching of materials and properties can be realized by laser deposited welding with powder feeding,which provides an effective way for the forming and functional gradient repairing of metal components.