Fe-C-Si-B合金连续激光非晶化层的组织构成研究

Research on Constitution of the cw Laser Glazed Fe C Si B Eutectic Alloy Layer

在铸铁表面Ｆｅ－Ｃ－Ｓｉ－Ｂ激光共晶合金化层上获得了许多表征非晶态的白亮层，其中最大的占整个熔池面积的８０％以上。共晶基体外延生长层的突然中断是得到白亮层的首要条件。经透射电镜和高分辨率扫描电镜分析发现，白亮层由结构不同的三个亚层组成：表层为均匀的纳米晶，中部为非晶态，底层是不均匀的纳米晶。

Bright layers covering 80% of the melt area have been achieved by laser glazing on Fe C Si B eutectic matrix prealloyed by laser on cast iron substrates. The bright layers appear only when the epitaxial growth from the Fe C Si B eutectic matrix stops abruptly during solidification. It is proved by TEM and HR SEM analyses that the bright layer consists of three sublayers: the upper sublayer is homogeneous nanocrystalline, the middle sublayer is metallic glass, and the lower sublayer is heterogeneous nanocrystalline.