Minasyan T, Aydinyan S, Toyserkani E, Hussainova I
Department of Mechanical and Industrial Engineering, Tallinn University of Technology, Ehitajate 5, 19086 Tallinn, Estonia.
Multi-Scale Additive Manufacturing Laboratory, Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave., West Waterloo, ON N2L 3G1, Canada.
Materials (Basel). 2020 Oct 29;13(21):4849. doi: 10.3390/ma13214849.
Mo(Si,Al) composites were produced by a pulsed laser reactive selective laser melting of MoSi and 30 wt.% AlSi10Mg powder mixture. The parametric study, altering the laser power between 100 and 300 W and scan speed between 400 and 1500 mm·s, has been conducted to estimate the effect of processing parameters on printed coupon samples' quality. It was shown that samples prepared at 150-200 W laser power and 400-500 mm·s scan speed, as well as 250 W laser power along with 700 mm·s scan speed, provide a relatively good surface finish with 6.5 ± 0.5 µm-10.3 ± 0.8 µm roughness at the top of coupons, and 9.3 ± 0.7 µm-13.2 ± 1.1 µm side surface roughness in addition to a remarkable chemical and microstructural homogeneity. An increase in the laser power and a decrease in the scan speed led to an apparent improvement in the densification behavior resulting in printed coupons of up to 99.8% relative density and hardness of ~600 HV1 or ~560 HV5. The printed parts are composed of epitaxially grown columnar dendritic melt pool cores and coarser dendrites beyond the morphological transition zone in overlapped regions. An increase in the scanning speed at a fixed laser power and a decrease in the power at a fixed scan speed prohibited the complete single displacement reaction between MoSi and aluminum, leading to unreacted MoSi and Al lean hexagonal Mo(Si,Al) phase.
通过对MoSi和30 wt.% AlSi10Mg粉末混合物进行脉冲激光反应选择性激光熔化制备了Mo(Si,Al)复合材料。进行了参数研究，将激光功率在100至300 W之间变化，扫描速度在400至1500 mm·s之间变化，以评估加工参数对打印试样质量的影响。结果表明，在150 - 200 W激光功率和400 - 500 mm·s扫描速度下制备的试样，以及250 W激光功率和700 mm·s扫描速度下制备的试样，在试样顶部具有相对良好的表面光洁度，粗糙度为6.5±0.5 µm - 10.3±0.8 µm，侧面表面粗糙度为9.3±0.7 µm - 13.2±1.1 µm，此外还具有显著的化学和微观结构均匀性。激光功率的增加和扫描速度的降低导致致密化行为明显改善，从而得到相对密度高达99.8%、硬度约为600 HV1或约560 HV5的打印试样。打印部件由外延生长的柱状树枝状熔池核心和重叠区域形态转变区之外的较粗树枝状组成。在固定激光功率下扫描速度的增加和在固定扫描速度下功率的降低阻止了MoSi与铝之间的完全单置换反应，导致未反应的MoSi和贫铝的六方Mo(Si,Al)相。
