Nanostructures Integrated Laser Shock Peening (nLSP) Processes and Their Mechanisms for Enhanced Fatigue Performance

纳米结构集成激光冲击强化 (nLSP) 工艺及其增强疲劳性能的机制

• 批准号: 0900327
• 负责人: Gary Cheng
• 金额: $ 35万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0900327&HistoricalAwards=false
• 关键词: Nanostructures; Integrated; Laser; Shock; Peening

The research objective of this award is to investigate an innovative hybrid process combining laser shock peening with creation of nanostructures to minimize the relaxation of compressive residual stresses and work hardening. This project will discover the fundamental process mechanisms of the nanoparticle integrated laser shock peening process, and understand how this process produces the unique micro/nanostructures, which results in stabilized residual stresses and work hardening. Experiments and simulations will be conducted to investigate the effects of the type, size and distribution of the nanoparticles on the resulting microstructure and residual stress distribution. The stability of residual stress and dislocation structure under different temperatures and cyclic loadings will be studied using transmission electron microscopy and X-ray diffraction. Dislocation-pinning mechanisms will be investigated to explain the stabilizing effects. In order to study the mechanism of fatigue life enhancement, we will build a fatigue life model to predict the improved fatigue life considering the time variant residual stresses and hardness under real service conditions. Fatigue testing experiments will be designed to validate this model.The successful completion of this work will make an improvement to laser shock peening that produces compressive residual stress and a work hardening layer. This work can ensure the benefit of integrating a pre-stressing concept into component design with minimum risk for improved fatigue life, increased reliability and reduced weight. The impact can be transferred to the majority of load-carrying and structural components. This project will meet the challenges of education in materials science, engineering and manufacturing by (a) enhancing interdisciplinary and nontraditional manufacturing for research and education in Purdue University, (b) providing a multidisciplinary research opportunity for students to advance discovery and understanding of cutting edge manufacturing processes and (c) outreach to undergraduate and graduate students to retain them in science and engineering, especially underrepresented and minority students.

该奖项的研究目的是调查一种创新的混合过程，该过程结合了激光冲击与创建纳米结构的创建，以最大程度地减少压缩残留应力和工作硬化的放松。 该项目将发现纳米颗粒的基本过程机制集成激光冲击过程，并了解该过程如何产生独特的微/纳米结构，从而导致稳定的残留应力和工作硬化。 将进行实验和模拟，以研究纳米颗粒对所得微观结构和残留应力分布的类型，大小和分布的影响。 将使用透射电子显微镜和X射线衍射研究在不同温度和循环载荷下残留应力和脱位结构的稳定性。 将研究脱位机制，以解释稳定效应。 为了研究疲劳寿命增强的机制，我们将建立一个疲劳寿命模型，以预测在实际服务条件下的时间变异的残留应力和硬度，以预测疲劳寿命的改善。 将设计疲劳测试实验来验证该模型。这项工作的成功完成将改善激光冲击式，从而产生压缩残留应力和工作硬化层。 这项工作可以确保将预压力概念纳入组件设计的好处，并具有最小的疲劳寿命，可靠性提高和减轻体重的风险。影响可以转移到大多数载荷和结构组件中。 该项目将面临（a）加强普渡大学研究和教育的材料科学，工程和制造业的教育挑战，（b）为学生提供了多学科的研究机会，以提高发现和了解最先进的制造过程的发现和理解，并在较小的学生中毕业，从事较小的学生和毕业的学生，​​并在科学和培训中毕业，尤其是在科学和培训中。