铸铁表面抗裂耐磨激光熔敷材料的研制

采用铁基熔敷材料 ,在不预热情况下通过调整熔敷金属Ni含量 ,改变铸铁激光熔敷层内奥氏体相与渗碳体相体积分数 ,进而抑制熔敷层裂纹的产生。在抗裂性最佳激光熔敷工艺参数基础上 ,研究了Ni对熔敷层奥氏体体积分数及表面裂纹率的影响 ,揭示了熔敷层开裂的微观机制 ,获得了搭接 2 5道熔敷层不裂的Fe C Si Ni系熔敷材料。以此熔敷材料为基础 ,改变钛粉含量 ,在熔敷层得到原位自生TiC ,研究了TiC对熔敷层耐磨性的影响 ,分析了TiC数量对熔敷层磨损形貌及磨损质量损失的影响规律 ,最终获得了可显著提高熔敷层抗裂性及耐磨性的Fe C Si Ni Ti熔敷材料。

Development of Laser Cladding Materials with Crack Resistance and Wear Resistance in Clad Layer of Grey Iron

To avoid the forming of cracks in iron based laser cladding, the volume fractions of austenite and cemetite in cladding layers were adjusted through adjusting the contents of Ni. The claddings were produced on gray irons without preheating. Based on the optimum parameters of laser processing, the effects of Ni contents on the volume fraction of austenite and surface cracking were investigated, the cracking mechanisms were revealed, and a sort of Fe C Si Ni cladding material was obtained which could form crack free 25 pass cladding layers on iron. By adding Ti powders into the Fe C Si Ni cladding material, endogenous TiC could form in cladding layers. The effects of endogenous TiC on wear resistance of cladding layers were also investigated. As a result, Fe C Si Ni Ti cladding materials were obtained which could improve the cracking and wear resistance significantly.