Low modulus-yet-hard, deformable multicomponent fibrous B2-phase making a medium-entropy alloy ultra-strong and ductile

被引：10

作者：

Zhang, D. D. ^{[1
]}

Zhang, J. Y. ^{[1
]}

Kuang, J. ^{[1
]}

Liu, G. ^{[1
]}

Sun, J. ^{[1
]}

机构：

[1] Xi An Jiao Tong Univ, State Key Lab Mech Behav Mat, Xian 710049, Peoples R China

来源：

SCRIPTA MATERIALIA | 2023年 / 222卷

基金：

中国国家自然科学基金;

关键词：

Medium-entropy alloy; Heterogeneous microstructure; Strengthening mechanisms; Modulus mismatch; Fracture behavior; STRENGTHENING MECHANISMS; DISLOCATION; PHASE; COMPOSITES; PLASTICITY; EVOLUTION;

D O I：

10.1016/j.scriptamat.2022.115058

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Introducing inclusions as the strength enhancer is an effective method to develop ultrastrong-yet-ductile metallic composites. However, the widely used high modulus hard-and-brittle inclusions in the low modulus matrix for strengthening often cause hetero-phase cracking and resultant reduced ductility of inclusion-reinforced com-posites. Here we present a novel strategy to design ultrastrong and ductile heterogeneous NiCoCr-based medium -entropy alloy uniting high modulus-yet-soft equiaxial-grained matrix combined with low modulus-yet-hard fibrous B2-inclusions. The image stress effect induced by the modulus mismatch can weaken the matrix/B2 interfacial resistance for dislocation transmission into the hard B2-phase, thus promoting their plasticity. Meanwhile, the strong matrix can effectively arrest cracks in B2-inclusions nucleated at their ideal strength to realize large ductility and great fracture resistance of composites. The fracture behavior of our designed alloys related to the fibrous B2-inclusions was rationalized in terms of the stress transfer theory. This work provides a novel pathway for designing high-performance multicomponent alloys even metallic composites utilizing the ideal strength of low modulus-yet-hard inclusions.

引用

页数：7