A unified model for ductile-to-brittle transition in body-centered cubic metals  

作　　者：Yu-Heng Zhang En Ma Jun Sun Wei-Zhong Han 

机构地区：[1]State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China

出　　处：《Journal of Materials Science & Technology》2023年第10期193-198,共6页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.51922082 and 51971170)and the“111 Project"of China 2.0(Grant No.BP0618008).E.M.acknowl-edges XJTU for hosting his work at the Center for Alloy Innovation and Design。

摘　　要：Ductile-to-brittle transition(DBT)is a well-known phenomenon in body-centered-cubic(BCC)metals,in-termetallics and semiconductor materials.A quantitative prediction of the DBT temperature,however,has so far remained intractable.Here,we propose a unified model based on the efficacy of dislocation multi-plication as the controlling factor for DBT,with the dislocation source efficiency governed by the relative mobility of screw versus edge dislocations.The model successfully predicts the DBT temperature of iron,molybdenum and tungsten,and also covers the influence of grain size,initial dislocation density,and the multiplicity of dislocation sources.A comparison with experiments indicates that the model captures the key DBT features,providing new insight into the toughness of BCC metals.

关 键 词：METALS DUCTILE BRITTLE DISLOCATION MOBILITY 

分 类 号：TG113[金属学及工艺—物理冶金]