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 这项理论/实验相结合的研究涉及解理断裂中脆性转变 (BDT) 的建模。 将通过检查裂纹尖端发生的两个竞争过程来研究控制 BDT 的内在机制：导致脆性断裂的解理裂纹扩展和在延性断裂过程中产生的固有塑性变形期间发生的位错生成。 将采用一种新颖的实验技术，其中涉及在温度梯度场中生长解理裂纹并测量由于位错产生而导致的裂纹停止。 我们将寻求对这种现象的基本理解所必需的三个信息：转变温度、转变发生时的裂纹速度以及伴随转变的裂纹尖端的位错结构。 ***