RIA: Experimental Investigation of Brittle to Ductile Transition in Cleavage Fracture

这项RIA奖的研究目的是利用一种新的实验技术，提供脆性到延性转变（BDT）过程中出现的基本机制的信息。需要解决的问题是：(1)BDT是由裂纹尖端位错形核控制还是位错迁移控制；(2)导致BDT的临界裂纹尖端位错构型是什么；(3) BDT的应变率灵敏度是多少；(4)杂质对BDT的影响。

The purpose of the research to be performed on this RIA award is to provide information on fundamental mechanisms that manifest during the brittle-to-ductile transition (BDT) process using a novel experimental technique. The issues to be addressed are: (1) whether BDT is controlled by crack tip dislocation nucleation or dislocation mobility; (2) what are the critical crack tip dislocation configurations that result in BDT; (3) what is the strain rate sensitivity of the BDT; and (4) what are the effects of impurities on the BDT.