Laser-based additive manufacturing of bulk metallic glasses: A review on principle, microstructure and performance

Abstract

Bulk metallic glasses (BMGs) have gained significant attention in the engineering field due to their unique microstructure and excellent properties. However, the fabrication of large-sized and complex-shaped BMGs components remains a major challenge. Laser-based additive manufacturing (LAM) techniques offer a promising solution to conquer the limitations of traditional methods in manufacturing BMGs. Theoretically, LAM techniques can achieve extremely high cooling rates of over 10⁴ K/s, resulting in the formation of metallic glass structures within the tiny molten pools. More significantly, the bottom-up concept of LAM enables the layer-by-layer construction of large-sized BMGs parts. Herein, this review extensively explores cutting-edge research on various aspects of utilizing LAM techniques in BMGs fabrication. It provides a comprehensive discussion of the forming mechanism of BMGs during LAM, focusing on factors such as heterogeneous microstructure, crystallization behavior and defect elimination. Additionally, the influence of composition and process parameters on the performance of LAM-produced BMGs, including mechanical properties, corrosion behavior, and biocompatibility, is systematically reviewed. An outlook on the LAM techniques for BMGs production is presented, aiming to provide some guiding principles for future research directions in this pioneering field.