论文部分内容阅读
以铁基合金粉和铝粉为原料,采用激光熔覆反应合成工艺在低碳钢基体表面制备Fe-Al合金覆层。利用扫描电镜、能谱仪、透射电镜以及X射线衍射实验方法等对熔覆合金层以及与钢基体的结合界面等进行了显微组织与相结构的分析。结果表明:采用激光熔覆反应合成Fe-Al合金工艺在1.5～2.1kW的熔覆功率范围内获得了与基体之间良好冶金结合的Fe-Al合金覆层,覆层组织致密,含少量孤立微孔隙,但无裂纹缺陷;Fe-Al覆层组织主要为细密、均匀的树枝晶,树枝主晶是固溶有一定量Cr、Ni、Si,化学成分满足Fe_3Al中Fe与Al原子配比范围的α-Fe固溶体,其中各元素的原子比Fe:Al:Ni:Cr:Si大约为55:24:8:8:5。
Fe-Al alloy coating was prepared on the surface of mild steel by laser cladding reaction synthesis using iron-based alloy powder and aluminum powder as raw materials. The microstructure and phase structure of the clad layer and the interface with the steel substrate were analyzed by SEM, EDS, TEM and X-ray diffraction. The results show that the Fe-Al alloy coating with good metallurgical bonding with the matrix is obtained in the cladding power range of 1.5 ~ 2.1kW by laser cladding reaction of Fe-Al alloy. The coating has a dense structure with a small amount of isolated Micro-pores but no crack defects. The main microstructure of Fe-Al coating is fine and uniform dendrites. The main crystal of the dendrites is solid solution with a certain amount of Cr, Ni and Si. The chemical composition satisfies the range of Fe and Al atomic ratio in Fe 3 Al α-Fe solid solution in which the atomic ratio Fe: Al: Ni: Cr: Si of each element is about 55: 24: 8: 8: 5.