Yang Z, Wang H, Krauß S, Huber F, Merle B, Schmidt M, Markl M, Körner C (2022)
Publication Language: English
Publication Type: Journal article, Original article
Publication year: 2022
Book Volume: 589
Article Number: 121649
Selective laser melting (SLM), taking advantage of its inherent rapid cooling rates and near-net-shape forming ability, has been employed to fabricate bulk metallic glasses (BMGs). However, crystallization is frequently triggered during the SLM process, which results in the loss of advantageous properties of BMGs, such as extremely high hardness and near-theoretical yield strength. Although many studies have been conducted to investigate SLM of BMGs, there is still a lack of knowledge about the microstructural and compositional evolution during the laser beam processing, particularly the micromechanical property response upon crystallization.
In the present work, a systematic investigation is performed to gain a much better understanding about the evolution of microstructure and composition as well as the corresponding micromechanical property change during multiple laser beam melting. The material used in this study is an industrial-grade Zr-based BMG Zr59.3Cu28.8Al10.4Nb1.5 (AMZ4) with two different oxygen levels. AMZ4 demonstrates its good thermal stability by the fact that observable crystalline structure appears around the melt pool only after more than once laser beam treatment. The compositional stability of AMZ4 is manifested by the homogeneous elemental distribution on the melt pool area after even twenty-five laser beam remelting. The laser-metal interaction, melting and subsequent solidification are not effectively influenced by the emerging and expanding of crystallization zone (or heat affected zone, HAZ). Higher oxygen content results in not only a larger HAZ but also more quenched-in nuclei at the melt pool bottom. The HAZ does not exhibit a fully crystallized structure, but rather has a mixture of amorphous and crystalline phases. Crystallization of AMZ4 leads to an increase in hardness and Young’s modulus of the material.
Yang, Z., Wang, H., Krauß, S., Huber, F., Merle, B., Schmidt, M.,... Körner, C. (2022). Evolution of an industrial-grade Zr-based bulk metallic glass during multiple laser beam melting. Journal of Non-Crystalline Solids, 589. https://dx.doi.org/10.1016/j.jnoncrysol.2022.121649
Yang, Zerong, et al. "Evolution of an industrial-grade Zr-based bulk metallic glass during multiple laser beam melting." Journal of Non-Crystalline Solids 589 (2022).