为了获得激光表面改性的最佳扫描速度,以工程上应用较广的AZ91D镁合金为基材,检测了采用不同扫描速度进行激光处理的镁合金试样的组织,系统分析了改性层组织随激光扫描速度的变化规律。结果表明:随着激光扫描速度的增加,改性层中β-Mg17Al12的含量降低,树枝状晶的尺寸也随之减小且具有定向凝固的分布特征。

In order to obtain the optimal scanning speed of laser surface modification, taking the AZ91D magnesium alloy with wider engineering application as the substrate, the organization of the laser modified alloy sample by different scanning speed was measured, the variation of modified layer structure with laser scanning speed was analyzed. The results show that: with the increase of the laser scanning speed, the content of β-Mg17Al12 in modified layer and the size of the dendrites reduce, and it has the distribution characteristics of directional solidification.