块体非晶合金的韧塑化

块体非晶合金因其独特的原子结构而具有许多优异的力学性能,成为近年来材料领域的研究热点之一,但是由于其在变形过程中的室温脆性和应变软化等关键问题一直制约着其实际工程应用.为解决此问题,块体非晶合金领域的研究者们提出了多种方案,包括通过在非晶合金中调控其内禀特性如弹性常数、结构不均匀性,通过外加手段改变其应力及缺陷状态,通过外加和内生的方法在非晶基体中引入晶态增强相等方式,获得了一系列力学性能优异的块体非晶合金及其复合材料.特别是利用"相变诱导塑性"(transformation-induced plasticity,TRIP)概念研制出的块体非晶合金复合材料,同时具有大的拉伸塑性和加工硬化能力.本文围绕块体非晶合金的韧塑化这个关键科学问题,对单相非晶及非晶复合材料的韧塑化方案及机理进行了综述,着重介绍了TRIP韧塑化块体非晶合金复合材料的制备、性能、组织调控及韧塑化机理等,并对此领域的未来发展进行了展望.

Ductilization of bulk metallic glassy material and its mechanism

Bulk metallic glass has aroused intensive interest due to its unique atomic structure and properties, while its structural application is restricted by the shortcomings of its mechanical properties-room temperature brittleness and strain softening. To make up for these shortcomings, various approaches have been proposed, including tailoring intrinsic parameters such as elastic modulus and structural heterogeneity, and changing stress state or defect concentration. Bulk metallic glass composites with ex-situ added or in-situ formed crystallites have been fabricated, series of bulk metallic glasses and their composites with good mechanical properties have been designed, especially TRIP (Transformation-induced plasticity)-reinforced bulk metallic glass composites with large tensile ductility and work-hardening. In this paper, we review the ductilization of bulk metallic glass and its composites, as well as the related mechanism. Particularly, fabrication, properties, structure control and the ductilization mechanism of TRIP-reinforced bulk metallic glass composite are introduced in detail. A perspective of the challenges of ductilization of bulk metallic glassy materials is also mentioned briefly.