A Markov-Chain Model for Intergranular Stress Corrosion Cracking

晶间应力腐蚀开裂的马尔可夫链模型

• 批准号: 9704471
• 负责人: Tamara Olson
• 金额: $ 3.98万
• 依托单位: Michigan Technological University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-15 至 2000-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9704471&HistoricalAwards=false
• 关键词: Markov; Chain; Model; Intergranular; Stress

Olson 9704471 The proposed research develops a new model of intergranular stress corrosion cracking of metals, based on measurable features of the polycrystalline microstructure. In the model, the crack is viewed as proceeding through a network of grain boundaries, causing failure when the crack percolates through the material. The first phase of this project will be to compare various models for interface energy. This analysis will largely be a statistical analysis of data obtained from cracked samples, followed by a comparison and modification of the existing interfacial energy models. Next, the model will be used to compare the resistance to cracking of various microstructures. The microstructures to be tested will include random textures, textures simulated through numerical models of annealing, and textures from actual materials measured by Brent Adams' experimental group at Carnegie Mellon University. The results for textures from simulated processing models will predict the net effect of material processing on material performance. The lifetime of many engineering materials (for example, metals and metal alloys) is seriously limited by their susceptibility to the phenomenon called stress corrosion cracking. This type of failure occurs when the material is subject to a combination of tensile stress and a corrosive element, leading to a crack which propagates through the material and causes it to break. The main objective of the proposed research is to develop and analyze a new model of intergranular stress corrosion cracking. This model is used to predict the growth of cracks in metals and metal alloys, and it is unique in that it incorporates measurable microstructural information from the material. Because stress corrosion cracking is a common and catastrophic phenomenon in certain materials, it would be invaluable for engineers to be able to estimate a material's susceptibility to cracking by measuring microstructure and u sing the model. In addition, if one can correlate given processing techniques with the resulting microstructures, one could then use this model to prescribe processes which would enhance resistance to stress corrosion cracking.

奥尔森9704471 提出的研究开发了一种新的模型，金属晶间应力腐蚀开裂的多晶显微组织的可测量的功能的基础上。 在该模型中，裂纹被视为通过晶界网络进行，当裂纹扩展通过材料时导致失效。 该项目的第一阶段将是比较各种 界面能模型 这种分析将主要是对从破裂样品中获得的数据进行统计分析，然后对 现有的界面能模型。 接下来，该模型将 用于比较各种材料的抗裂性 微观结构 待测试的微结构将 包括随机纹理、通过 退火的数值模型，以及来自实际 由布伦特亚当斯的实验组测量的材料， 卡内基梅隆大学。 纹理的结果来自 模拟加工模型将预测材料加工对材料性能的净影响。 许多工程材料的寿命（例如， 金属和金属合金）受到严重限制， 他们对压力现象的敏感性 腐蚀开裂 这种类型的故障发生时，材料受到拉伸的组合， 应力和腐蚀性元素，导致裂纹， 通过材料传播并导致其断裂。 提出的研究的主要目标是开发和分析一种新的晶间应力腐蚀开裂模型。 该模型用于预测裂纹的扩展 在金属和金属合金中，它是独一无二的，因为它结合了可测量的微观结构信息， 材料。 由于应力腐蚀开裂是常见的 和灾难性的现象在某些材料中，这将是非常宝贵的工程师能够估计材料的敏感性裂纹通过测量微观结构和使用模型。 此外，如果一个人可以将给定的 具有所得微结构的加工技术， 然后，可以使用该模型来规定 将增强抗应力腐蚀开裂性。