工艺参数对选区激光熔化In625合金表面形貌影响的研究

Research on Influence of Process Parameters on Surface Morphology of In625 Alloy Fabricated by Selective Laser Melting

通过单层单道的方法研究了工艺参数对In625镍基高温合金选区激光熔化成型过程中熔线连续性的影响。研究过程中引入了变异系数来表征熔线宽度的均匀程度,分析了扫描速度和激光功率对熔线宽度、熔线均匀性以及熔线表面形貌的影响。结果表明,熔线连续性变化的主要原因是球化及飞溅现象的发生,其中扫描速度对球化及飞溅现象均有影响,而激光功率主要影响球化现象的发生。激光功率在50~70 W时,熔线宽度及表面质量变化较大,成型件质量难以控制。激光功率在70~100 W时,相同功率下,随着扫描速度的增大,飞溅及球化现象越来越严重,熔线宽度逐渐降低,连续性及表面质量也越差;相同扫描速度下,激光功率越低,熔线球化现象发生越频繁,熔线宽度降低表面质量变差。为达到较好的成型质量,扫描速度控制在500~1000 mm/min,激光功率在70~100 W。

The effects of process parameters on the continuity of In625 nickel-based superalloy fuse in selective laser melting process were studied by single-layer single-channel method. The coefficient of variation was introduced to characterize the uniformity of the width of the fuse. The effects of scanning speed and laser power on the width, uniformity and surface morphology of fuse were systematically analyzed. The results show that the main reason for the change of the continuity of the fuse is the occurrence of spheroidization and splashing. The scanning speed has an effect on the spheroidization and splash phenomenon, and the laser power mainly affects the occurrence of the spheroidization. When the laser power is 50-70 W, the width of the fuse and the surface quality change greatly, and the quality of the formed part is difficult to control. When the laser power is within the range of 70-100 W the splash and spheroidization phenomenon become more and more serious with the increase of scanning speed under the same power, meanwhile, the width of fuse decreases gradually, the continuity and surface quality become worse. The lower the laser power is at the same scanning speed, the more frequent the spheroidization phenomenon occurs, the lower the width of the fuse is, and the worse the surface quality is. In order to achieve better molding quality, the scanning speed should be controlled from 500 mm/min to 1000 mm/min, and the laser power should be between 70 W and 100 W.