Experimental analysis of spatter generation and melt-pool behavior during the powder bed laser beam melting process
Experimental analysis of spatter generation and melt-pool behavior during the powder bed laser beam melting process
复制标题
DOI：
10.1016/j.jmatprotec.2017.08.012
复制
发表时间：
2018-01-01
影响因子：
6.3
通讯作者：
Fabbro, R.
中科院分区：
文献类型：
--
作者：
Gunenthiram, V.;Peyre, P.;Fabbro, R.
飞溅形成的实验分析是在仪表式SLM装置上进行的，允许对飞溅喷射进行量化，并可能与熔池行为相关联。考虑到与SLM机器上进行的SLM条件几乎相似，316L不锈钢上的大飞溅(>；80微米)随着体积能量密度(VED)的增加而明显增加，这归因于金属蒸发对熔池施加的反冲压力以及由此产生的高速蒸汽羽流。在第二步中，Al-12Si粉床上的飞溅比316L粉床上的要低得多。对粉床的快速摄像分析表明，液滴的形成主要是在靠近熔池界面的粉床中开始的。在Al-12Si合金上，这样的液滴直接结合到MP中，而不像在316L上那样以飞溅的形式向上喷射。最后，研究表明，即使在316L上，通过使用低VED和较大的斑点(约0.5 mm)，也可以显著减少飞溅，允许在导电区熔化足够深的层，并确保层之间有足够的稀释。
The experimental analysis of spatter formation was carried out on an instrumented SLM set-up allowing the quantification of spatter ejections and possible correlation with melt-pool behavior. Considering nearly similar SLM conditions than those carried out on SLM machines, an increase of large spatters (> 80 mu m) with volume energy density (VED) was clearly demonstrated on a 316L stainless steel, which was attributed to the recoil pressure applied on the melt-pool by the metal vaporization and the resulting high velocity vapor plume. In a second step, much lower spattering was shown on Al-12Si powder beds than on 316L ones. Fast camera analysis of powder beds indicated that droplet formation was mostly initiated in the powder-bed near the melt-pool interface. On Al-12 Si alloys, such droplets were directly incorporated in the MP without being ejected upwards as spatters like on 316L. Last, it was shown that a strong reduction of spattering was possible even on 316L, with the use of low VED combined with larger spots (approximate to 0.5 mm), allowing to melt sufficiently deep layers in conduction regime and ensure adequate dilution between layers.