摘要
文章通过全因素试验探究了激光选区熔化技术(SLM)中激光功率和扫描速度对NiTi合金试样致密度及裂纹缺陷的影响规律,通过体能量密度综合评判了工艺参数对成形质量的影响。结果表明,随着体能量密度增大,致密度呈先增后减的趋势,试样表面出现由微观裂纹缺陷到无缺陷再到宏观裂纹缺陷的变化。当体能量密度处于75 J/mm^(3)至95 J/mm^(3)之间时,致密度维持在99.7%以上;随着激光功率的增大或扫描速度减小,试样致密度整体呈先增后减趋势;通过探究体能量密度相同时激光功率和扫描速度对样件成形质量的影响,发现激光功率大于等于270 W、扫描速度大于等于900 mm/s或激光功率小于等于90 W、扫描速度小于等于300 mm/s时,试样致密度均低于99.5%,出现匙孔和微裂纹;激光功率为180 W,扫描速度为600 mm/s时致密度则高于99.5%,无明显缺陷。
In this paper,the effects of laser power and scanning speed on the density and crack defects of NiTi alloy samples in selective laser melting(SLM)were investigated by all factor tests,and the effects of process parameters on the forming quality were evaluated comprehensively by the energy mass density.The results show that with the increase of energy density,the induced density increases first and then decreases,and the surface of the sample changes from microscopic crack defect to no defect and then to 3 macroscopic crack defect.When the physical mass density is between 75 J/mm and 95 J/mm^(3),the density is maintained above 99.7%.With the increase of laser power or the decrease of scanning speed,the density of the sample increases first and then decreases.By exploring the influence of laser power and scanning speed on the forming quality of the sample with the same physical mass density,it is found that when the laser power is greater than or equal to 270 W,scanning speed is greater than or equal to 900 mm/s,laser power is less than or equal to 90 W,scanning speed is less than or equal to 300 mm/s,the density of the sample is lower than 99.5%,and keyholes and micro-cracks appear.When the laser power is 180 W and the scanning speed is 600 mm/s,the density is higher than 99.5%and there are no obvious defects.
作者
徐晨
李志永
张威
郑府
柴明霞
XU Chen;LI Zhiyong;ZHANG Wei;ZHENG Fu;CHAI Mingxia(School of Mechanical Engineering,Shandong University of Technology,Zibo 255000,CHN)
出处
《制造技术与机床》
北大核心
2023年第11期148-153,共6页
Manufacturing Technology & Machine Tool