Fundamental Study of Brittle-to-Ductile Transition

脆性转变的基础研究

• 批准号: 9522661
• 负责人: K. Jimmy Hsia
• 金额: $ 19.23万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-10-01 至 1999-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9522661&HistoricalAwards=false
• 关键词: Fundamental; Study; Brittle; Ductile; Transition

9522661 Hsia This combined theoretical/experimental study involves the modelling of brittle-to-ductile transition (BDT) in cleavage fracture. The intrinsic mechanisms controlling the BDT will be studied by examining two competing processes that occur at crack tips: cleavage crack propagation which results in brittle fracture and dislocation generation which occurs during the inherent plastic deformation that develops during ductile fracture. A novel experimental technique will be employed which involved growing a cleavage crack in a temperature gradient field and measuring the crack arrest due to dislocation generation. Three pieces of information essential to the fundamental understanding of this phenomena will be sought: the transition temperature, the crack velocity when the transition occurs, and the dislocation structure at the crack tip which accompanies the transition. ***

9522661 HSIA这种合并的理论/实验研究涉及在裂解骨折中脆性到延性过渡（BDT）的建模。 控制BDT的固有机制将通过检查裂纹尖端上发生的两个竞争过程：裂解裂纹传播，从而导致脆性断裂和脱位产生，这些裂缝和脱位产生在延性裂缝过程中固有的塑性变形过程中发生。 将采用一种新型的实验技术，其中涉及在温度梯度场中种植裂解裂纹并测量由于脱位产生而导致的裂纹停滞。 将寻求对这种现象的基本理解必不可少的三种信息：过渡温度，发生过渡时的裂纹速度以及伴随过渡的裂纹尖端处的脱位结构。 ***