Evolution Mechanism of SS316L stainless steel powder in selective laser melting process

激光选区熔化成型SS316L不锈钢粉末演变机理 Evolution Mechanism of SS316L stainless steel powder in selective laser melting process 路超 LU Chao 1 first-author 肖梦智 XIAO Mengzhi 1 屈岳波 QU Yuebo 1 尹燕 YIN Yan 2 张瑞华 ZHANG Ruihua 1 3 钢铁研究总院 钢铁研究总院 Central Iron & Steel Research Institute Central Iron & Steel Research Institute 兰州理工大学省部共建有色金属先进加工与再利用国家重点试验室 兰州理工大学省部共建有色金属先进加工与再利用国家重点试验室 State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology 阳江市五金刀剪产业技术研究院 阳江市五金刀剪产业技术研究院 Hard-ware Knife Cut Industrial Technology Research Institute of Yangjiang Hard-ware Knife Cut Industrial Technology Research Institute of Yangjiang 研究SS316L不锈钢粉末多次循环使用后粉末特性的变化规律,阐明粉末颗粒形态及粒度的演变机理。结果表明,随着粉末循环使用次数的增加,粉末的粒径分布变窄,且粒径粗化;粉末松装密度和振实密度均有一定程度的提高,粉末流动性也较原始粉末有所改善,但豪斯纳比变化趋势与霍尔流速相反。循环使用的粉末颗粒表面成分发生严重氧化,粉末表面出现椭球形的氧化斑点和物理附着的金属蒸汽冷凝物。将循环粉末中出现的异形颗粒分为两类:第一类是激光诱导熔池飞溅颗粒,第二类是气体夹带诱导颗粒,并分别对两种异形颗粒的形成机理进行阐述。研究结果强调了在原材料的循环使用过程中粉末的氧化和异形颗粒的生成是不可避免的,未来需要更多地考虑异形颗粒、蒸汽冷凝物和氧化颗粒对成型件质量的影响。 The change rule of powder properties of SS316L stainless steel powder after recycling is studied,and the evolution mechanism of powder morphology and particle size distribution is clarified. The results show that as the number of powder cycles increases,the particle size distribution of the powder becomes narrow and coarser,the apparent density and tap density of the recycled powder are improved to a certain extent,and the flowability of the powder is also improved comparing with the original powder,but the change trend of Hausner’s ratio is opposite to that of Hall’s flow rate. The surface chemical components of recycled powder particles are oxidized severely,and the ellipsoidal oxidation spots and metal vapor condensate are found on the surface of powder particles. In this study,the irregular particles in the recycled powder are divided into two categories: the first is laser-induced molten pool spatter particles,the second is gas entrainment induced particles,and the formation mechanism of the two kinds of irregular particles is described respectively. The results of this study emphasize that in the recycling process of raw materials,the oxidation of powder and the generations of irregular particles are unavoidable.In the future,more consideration should be given to the effects of irregular particles,vapor condensates and oxide particles on the quality of the processed parts. 激光选区熔化 循环使用 氧化 粉末特性 演变机理 selective laser melting recycling oxidation powderproperties evolutionmechanism TG665 2022-03-08 7 50