以Al-TiB2复合粉体为强化层原料(其中铝为粘结剂), 采用Nd: YAG激光在镁钆系镁合金表面进行激光熔覆强化处理, 考察了TiB2含量对强化层组织、耐磨性及其与基体相容性的影响。结果表明: 强化层中铝元素与基体中的钆、钇等元素发生了原位反应, 生成了高温硬质相Al2Gd和Al2Y等金属间化合物, 且引入的强化相TiB2未发生分解, 与原位合成的金属间化合物及基体相容性良好, 但分布特点和结构差异显著; 当复合粉体中TiB2质量分数低于70%时, 强化层组织细小均匀; 强化层显微硬度随着TiB2含量的增加而增大, 比基体硬度提高4～6倍, 耐磨性能得到显著改善。

A pulsed Nd: YAG laser was employed to strengthen the surface of Mg-Gd magnesium alloy with raw material of Al-TiB2 composite micro powders (Al powders as the binders) by cladding. The effects of TiB2 content on the microstructure and abrasive resistance of the strengthened layer, the compatibility between the strengthened layer and substrate were investigated. The results show that the in situ reaction generated between Al from the strengthened layer and elements of Gd, Y in Mg alloy substrate, and the intermetallic compounds such as Al2Gd and Al2Y were in-situ generated. Meanwhile, it was not found the decomposition of the strengthening phase TiB2. The compatibility among matrix, intermetallic compounds by in-situ synthesis and introduced strengthening phase TiB2 was fairly excellent. However, their characteristics of distribution and structures were different significantly. The strengthened layer had fine and uniform microstructure when the TiB2 content in composite powders was less than 70wt%. The overall microhardness of the strengthened layer increased with increasing of TiB2 content and improved up to 4-6 times compared with the substrate. Furthermore, the wear resistance improved dramatically.