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“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 W6、.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 an important phenomenon in the process of laser direct metal forming (LMDF). It plays an important role in improving the forming accuracy of the part under open-loop control. In order to analyze the morphological self-healing ability of different materials, the main influencing factors were explored in order to guide the formulation of reasonable forming process and improve the forming accuracy. By using orthogonal experiment method, laser metal Direct forming technology to obtain multiple sets of single-channel thin-walled samples, analysis of the impact of process parameters on the size of the sample. The experimental results on 316L stainless steel show that there are significant differences in the self-healing ability of different morphologies in laser direct metal forming. The scanning speed is the main factor, followed by the laser power, and finally the amount of powder feeding. The self-healing ability of 316L stainless steel topography was significantly improved when the optimized laser power, scanning speed and powder feeding volume were 240 W6, .0 mm / s and 7.3 g / min, respectively. The maximum healing height exceeded 1.54 mm, The healing rate is 0.038 mm per layer.