# Non-Isothermal Crystallization Behavior of a Zr-Based Amorphous Alloy Composite Prepared by Selective Laser Melting

## TL;DR

This paper studies how a Zr-based alloy composite behaves during crystallization when made using laser melting, comparing it to its powdered form.

## Contribution

The study reveals new insights into the non-isothermal crystallization behavior of SLMed Zr-based amorphous alloy composites.

## Key findings

- Cu10Zr7 and CuZr2 are the crystallization phases in both gas-atomized powder and SLMed samples.
- Crystalline sizes increase linearly with laser energy density, and volume fractions follow an exponential trend.
- Gas-atomized powders show higher thermal stability and different crystallization difficulty compared to SLMed samples.

## Abstract

Zr48Cu47.5Al4Co0.5 bulk amorphous alloy composites were prepared by selective laser melting (SLM) technology under different processing conditions and their non-isothermal crystallization behaviors were systematically investigated. The results show that the crystallization phases are Cu10Zr7 and CuZr2 for both gas-atomized powder and SLMed samples. The dependence of volume fraction of Cu10Zr7 and CuZr2 on laser energy density can be fitted by an exponential function. The crystalline sizes of Cu10Zr7 and CuZr2 linearly increase with increasing energy density. The thermal stability is larger for the gas-atomized powders than for the SLMed bulk samples. It is interestingly found that there is an exponential relationship between the crystallization enthalpy ΔHx and the amorphous content. In addition, the glass transition is more difficult for the gas-atomized powders than for the SLMed bulk samples. The crystallization procedure is more difficult for the SLMed bulk samples than for the gas-atomized powders. The local activation energy Eα decreases with increasing α for the gas-atomized powder and the SLMed bulk samples. In addition, the Eα is larger for the SLMed bulk samples than for the gas-atomized powder at the corresponding crystallization fraction α. The dependence of the local Avrami exponent n(α) on the α is similar for both the gas-atomized powders and the SLMed bulk samples at studied heating rates. The crystallization mechanism is also discussed.