MODEL OF HEAT TRANSFER AND CRYSTALLIZATION KINETICS IN THE HEAT-AFFECTED ZONE IN VIT 106 ALLOY IN SELECTIVE LASER MELTING

Abstract

Metallic glasses are difficult materials to obtain as bulk products because of the need for rapid cooling to avoid crystallization. Bulk metallic glasses (BMGs) have lower cooling rates than metallic glasses, which allows one to obtain bulk structures but it is hard to achieve by traditional methods. Selective laser melting (SLM) is an additive manufacturing method that processes powders layer by layer to form a part from a three-dimensional model. In SLM, the cooling rate exceeds the critical cooling rate for BMGs, which suggests the possibility of applying SLM to BMG. The purpose of this work is to study the crystallization kinetics at SLM by theoretical analysis of a particular process example. Comparison of the calculations and the experiment indicates the amorphous structure of the remelted material, as well as the presence of a large number of crystal nuclei in the original material.