“形貌自愈合效应”是激光金属直接成形(LMDF)过程中的一个重要现象，在开环控制条件下对提高零件成形精度具有重要作用。为了分析不同材料的形貌自愈合能力，探寻主要影响因素，以指导制定合理成形工艺、提高成形精度，通过正交实验方法，在具有“凸起”特征的基板上，采用激光金属直接成形技术获得了多组单道薄壁试样，分析工艺参数对试样尺寸的影响规律。对316 L不锈钢的实验结果表明，激光金属直接成形中不同工艺参数对其形貌自愈合能力的影响有显著差别，其中扫描速度是主要影响因素，其次为激光功率，最后为送粉量。当优化的激光功率、扫描速度、送粉量分别为240 W、6.0 mm/s、7.3 g/min时，可以显著提高316 L不锈钢形貌自愈合能力，其最大愈合高度超过1.54 mm、愈合速率为每层0.038 mm。

"Self-healing effect" is one of the important phenomena in laser metal direct forming (LMDF) process, and plays an important role in improving the forming quality of parts under open-loop control. In order to study the self-healing ability of different materials, reveal main influencing factors, and provide guidance for formulating correct forming process to improve the forming precision, orthogonal experiment is designed to fabricate several thin-walled parts on substrate with "convex" characteristics in LMDF, and the influence of process parameters on sample dimension is analyzed. The experimental results on 316 L stainless steel show that the influence of different process parameters on the self-healing ability varies significantly: the traverse speed is the most important factor, the laser power next, and then the powder mass flow rate. The 316 L stainless steel self-healing ability can be improved remarkably when using optimized laser power, traverse velocity, and powder mass flow rate as 240 W, 6.0 mm/s, and 7.3 g/min, respectively. The maximum self-healing height exceeds 1.54 mm and the self-healing rate is 0.038 mm per layer.