Research progress in control of microstructure and mechanical properties of in-situ bulk metallic glass composites

Abstract

Metallic glasses (MGs) have a series of excellent mechanical, physical, chemical and other properties due to their unique short-range ordered and long-range disordered atomic structure characteristics, making them have great potential application value in the field of advanced metal structural materials. However, when the bulk metallic glass (BMG) is deformed under room temperature, the large amount of free volume formed by the shear transformation of the atomic clusters will evolve into a highly localized shear bands. The localized shear bands will undergo instability expansion due to the lack of media, which leads to the fact that BMGs are very prone to brittle fracture at room temperature. In particular, there is no plasticity during uniaxial tension. In order to overcome this shortcoming, the researchers proposed to introduce the micron-sized crystal phase into the glass matrix to suppress the instability expansion of the shear band, so that the in-situ dendritic toughened bulk metallic glass composite (BMGC) has obvious tensile plasticity, and the BMGC has attracted much attention from the material science community. In recent years, researchers have successively improved the plastic deformation ability of BMGC through composition design, preparation technology, heat treatment process and other methods, making BMGC be expected to move towards practical engineering applications. This article focuses on the key scientific issue of microstructure control of in-situ second-phase toughened BMGC, from the factors that affect the microstructure of BMGC (alloy composition design, preparation process parameters, microstructure construction, etc.) to the mechanism of the influence of microstructure on its room temperature mechanical properties, the research results were systematically summarized. In particular, the article focuses on the research progress in the field of in-situ second-phase toughened BMGC in the past 10 years in the field of microstructure regulation and the correlation between mechanical properties at room temperature. In addition, the current problems and challenges in the field of in-situ second-phase toughened BMGC were addressed. The prospects are expected to provide a theoretical reference for the design and preparation of high-strength and high-toughness in-situ second-phase toughened BMGC.

Keywords

• bulk metallic glass composites
• microstructure regulation
• preparative technique
• mechanical property
• shear band