摘要
块体非晶合金由于其短程有序、长程无序的结构特点,具有了一系列优异的机械特性和物理特性,被认为是一种潜在的结构材料并得到广泛研究。但其室温受载后易发生局域剪切所致的脆断,特别是在单轴拉伸时几乎没有任何塑性。为克服这个缺点,研究者们提出通过引入晶体相来抑制剪切带的失稳扩展,从而在非晶复合材料中获得了室温拉伸塑性。然而,大部分的Ti基、Zr基非晶复合材料晶体相中的位错强化作用不足以弥补非晶剪切软化作用,导致非晶复合材料在变形过程中发生软化颈缩现象,这很大程度上限制了非晶复合材料的实际工程应用。研究者们将传统钢铁材料中的强化机制,如相变(Transformation-induced plasticity, TRIP)或孪晶(Twining-induced pplasticity, TWIP)诱导塑性等,引入内生非晶复合材料中来改善其软化问题。由于这些强化机制的引入,非晶基体中多重剪切带萌生扩展导致的剪切软化作用被弥补,因此在CuZr基、Ti基等体系的非晶复合材料获得了明显的加工硬化能力和拉伸塑性。本文围绕内生非晶复合材料中的加工硬化行为这一关键科学问题,对非晶复合材料中几种常见的产生加工硬化的方法进行分类介绍,重点阐述了近10年来非晶复合材料领域加工硬化机制的研究进展,并且指出了目前非晶复合材料强韧化研究领域存在的问题和挑战,以期为强韧化内生非晶复合材料的设计与制备以及微观变形机制的研究提供参考。
Bulk metallic glass(BMG) exhibits excellent mechanical and physical properties owing to its short-range order and long-range disorder. Such glasses have been widely studied as potential structural materials. However, they are prone to brittle fracture when loaded at room temperature because they undergo local shearing at room temperature, especially under uniaxial tension, thereby lacking plasticity. To overcome this shortcoming, researchers have proposed that introducing a crystalline phase would suppress the instability expansion of the shear band, thereby ensuring the tensile ductility of BMG composites(BMGCs) at room temperature. However, in most in-situ Ti-and Zr-based BMGCs, the dislocation strengthening in the crystalline phase could not compensate for the shear softening effect in the glass matrix. The resultant softening and necking during deformation limit the practical engineering applications of BMGCs. Researchers have also proposed the strengthening mechanisms of traditional steel materials, such as transformation-induced plasticity or twining-induced plasticity for BMGCs. These strengthening mechanisms adequately compensate for the shear softening effect caused by the initiation and expansion of multiple shear bands in the glass matrix. The strengthened CuZr-and Ti-based BMGCs show obviously improved work-hardening ability and tensile plasticity. This work focuses on the key scientific problems related to the work-hardening behaviour of BMGCs, classifies and introduces several common methods for work hardening in BMGCs, and discusses the research progress on hardening mechanisms of BMGCs in the last decade. Moreover, current problems associated with the strengthening and hardening of BMGCs are discussed, providing a reference for the design and preparation of toughened in-situ BMGCs and the study of microscopic deformation mechanisms.
作者
翟海民
欧梦静
袁花妍
崔帅
李文生
ZHAI Haimin;OU Mengjing;YUAN Huayan;Cui Shuai;LI Wensheng(State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;School of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2022年第23期134-142,共9页
Materials Reports
基金
国家自然科学基金(51901092,52075234)
科技部丝绸之路经济带金属表面工程技术国家国际科技合作基金(2017D01003)
甘肃省青年科技基金计划(20JR5RA431)
兰州理工大学红柳优秀青年人才支持计划(26/062005)
湖南理工学院湖南省电磁装备设计与制造重点实验室开放基金资助课题(DC202001)。
关键词
内生非晶复合材料
加工硬化
应力诱导相变强化
应力诱导孪晶强化
位错强化
bulk metallic glass composite
work hardening
stress-induced phase transformation strengthening
stress-induced twinning strengthening
dislocation strengthening
