中文摘要：

用优化的工艺参数,在45钢基体上用激光合成了表面质量好的FeAl金属间化合物涂层.结果表明,多道搭接处理对涂层相组成无影响. 涂层外层 （约1/3涂层）组织为灰白相间的FeAl及基体上分布少量黑色针状FeAl3,里层只有FeAl.FeAl的组织生长形态为树枝晶,白色枝晶富Fe,灰色枝间富Al.涂层/基体界面清晰,呈凹凸状.能量分散谱仪（EDS）成分线扫描分析结果表明,从1/3涂层处Al、Fe开始缓慢过渡,结合区比合成区成分过渡明显,但梯度不大,涂层/基体间有明显互扩散,为冶金结合. 激光合成FeAl涂层的最高硬度为565 HV0.025,比基体高1.7倍.

英文摘要：

The FeAl intermetallic compound coating with good surface quality has been synthesized by laser beam on 45 steel substrate with optimal process parameters. The results show that the treatment of multi-track overlapping for the coating has no effects on phase constituent of the coating. The microstructure of the outer layer （ about one-third thickness of the whole coating） of the coating is a small amount of the black needle-like FeA13 distributed within the FeAl matrix with the grey and the white alternating, while there is only FeAl existing in the inner layer. The crystal morphology of FeAl is dendritic,white dendrites are Fe-rich, and grey interdendritics are Al-rich. The interface between the coating and the substrate is distinct and knaggy. The composition analysis results of the EDS line scanning show that the contents of Fe and Al begin to gradually transit by inches from the site of one-third thickness of the whole coating, transit more obviously in the bonded zone than in the synthesized zone, but the transition gradient is not too steep, illustrating that the atoms of constituent elements of the coating and the substrate diffuse each other, and the coating is metallurgically bonded to the substrate. The hardness of the laser-synthesized FeAl coating reaches 565 HV0.025,1.7 times higher than that of the substrate.