从宏观和微观两方面分析激光选区熔化设备零件打印中出现纵向裂缝的原因, 认为纵向裂缝的产生主要表现在激光扫描能量过低。通过测试扫描光路系统各项性能将问题定位于光路系统延时, 然后, 调试光路系统延时的参数保证打印零件上不存在裂缝。最后根据工艺试验的结果(成型零件的随炉样件致密度高达99.7%, 抗拉强度为626 MPa)验证零件纵向裂缝的影响因素之一为光路系统在该位置激光能量过低。

We analyze the causes of longitudinal cracks from macroscopic and microscopic aspects in selective laser melting. The result shows that the mainly reason is the low energy of laser scanning. Then, testing the performance of the scanning optical system, the problem is focused to the optical system delays. To ensure that the cracks disappeared on the printed parts, adjusted the parameters of the optical system delay. Finally, according to the results of the samples (the density of the samples is 99.7% and the tensile strength is 626 MPa), to verified the laser too low scanning energy at this position is one of the factors in the longitudinal crack of the selective laser melting.