AlSi10Mg/AlN Interface Grain Structure after Laser Powder Bed Fusion

Details and features of the grain structure near interface region between AlN ceramic phase AlSi10Mg matrix after laser powder bed fusion (LPBF) were investigated. Aluminum nitride particles obtained through self-propagating high-temperature synthesis mechanically mixed with aluminum powder. Optimization LPBF process parameters resulted in synthesized material free pores other defects. Optical microscopy analysis etched cross-section more detailed EBSD revealed regions relatively coarse grains at melting pool boundaries fine melt core particles. Moreover, a pronounced orientation elongated towards center particle was obtained. The such formed microstructure is attributed to directional heat sink during crystallization due higher thermal conductivity compared matrix. On contrary, poor wettability by partly prevented formation features, thus combination these factors determines final resulting material.