Amorphous-Crystalline Composite Microstructure Formation in Zr<sub>46</sub>Cu<sub>46</sub>Al<sub>8</sub> Alloy at the Conditions of Selective Laser Melting

Abstract

Amorphous alloys are promising structural materials because of their high mechanical strength. Their drawbacks are low ductility and severe size restrictions for components obtained by casting. Additive manufacturing by selective laser melting (SLM) consists in successive fusion of small portions of material to add to a growing part. Each portion is subjected to a short thermal cycle favorable for amorphization. Thus, one can build an amorphous part as large as necessary. We study the microstructure of cast samples of a zirconium-based bulk metallic glass after laser processing with the parameters typical for SLM. Scanning electronic microscopy has shown partial crystallization in the heat affected zone of the laser beam. The spatial distribution and the volume fraction of the crystalline phase can be controlled by laser processing parameters. The obtained amorphous-crystalline structures are promising to increase the ductility of bulk metallic glasses.