Collaborative Research: Plastic Ceramics: The Role of Grain Boundaries During Laser Shock Peening

合作研究：塑料陶瓷：晶界在激光冲击强化过程中​​的作用

• 批准号: 2023404
• 负责人: Bai Cui
• 金额: $ 15万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2023404&HistoricalAwards=false
• 关键词: Collaborative; Research; Plastic; Ceramics; Role

NON-TECHNICAL DESCRIPTION: Laser shock peening (LSP) is a new surface engineering method that has been proven to prevent crack growth in several ceramic materials, which are inherently brittle. In particular, success has been found with ceramics suitable for applications in extreme environments (e.g., hypersonic vehicles, gas-turbine engines, and armor). The general applicability of this technique is impeded because the underlying mechanisms are not fully understood. The goal of this project is to identify the role internal interfaces play during LSP to guide future material design, which will extend the applicability of this technique and increase its effectiveness at improving the ceramics’ mechanical performance. The next generation of ceramic engineers are being trained on these methods and approaches to enable the processing and implementation of tough structural ceramics. In addition to the two doctoral students, undergraduate and high school students are being recruited to participate in the project each summer. TECHNICAL DETAILS: This research identifies how grain boundary character (macroscopic parameters, thickness, and chemistry) in ceramics affects the propensity to form dislocations and, thus, build compressive residual stresses during LSP. LSP has been adapted to ceramic materials such as silicon carbide and alumina to induce compressive residual stresses that improve their crack resistance. Yet, the fundamental mechanisms and the broad applicability of the technique remain poorly understood. The scientific hypothesis is that LSP will be applicable to materials with higher order complexions – equilibrium grain boundary states with high disorder – to generate shock wave propagations that initiate dislocation formation necessary for building compressive residual stresses near grain boundaries. To test this hypothesis, the effect of LSP is being investigated in various grain boundaries of different character and composition in alpha-phase alumina with complexion engineering. The specific aims are to (1) correlate the extent of compressive residual stress induced by LSP with grain boundary character distributions and grain size and (2) identify individual grain boundary structures associated high dislocation density. Engineering students are learning valuable skills in ceramic processing and electron microscopy characterization.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术描述：激光冲击强化（LSP）是一种新的表面工程方法，已被证明可以防止裂纹扩展的几种陶瓷材料，这是固有的脆性。特别地，已经发现适合于在极端环境（例如，高超音速飞行器、燃气涡轮发动机和装甲）。这种技术的普遍适用性受到阻碍，因为根本的机制没有得到充分理解。该项目的目标是确定LSP过程中内部界面的作用，以指导未来的材料设计，这将扩展该技术的适用性，并提高其在改善陶瓷机械性能方面的有效性。下一代陶瓷工程师正在接受这些方法和途径的培训，以实现坚韧结构陶瓷的加工和实施。除了两名博士生外，每年夏天还招募本科生和高中生参加该项目。 技术规格：这项研究确定了陶瓷中的晶界特征（宏观参数、厚度和化学成分）如何影响形成位错的倾向，从而在LSP期间建立压缩残余应力。LSP已被应用于陶瓷材料，如碳化硅和氧化铝，以诱导压缩残余应力，提高其抗裂性。然而，该技术的基本机制和广泛适用性仍然知之甚少。科学假设是，LSP将适用于具有更高阶复杂性的材料-具有高度无序的平衡晶界状态-以产生冲击波传播，该冲击波传播启动在晶界附近建立压缩残余应力所必需的位错形成。为了验证这一假设，LSP的效果正在研究在不同的字符和组成的α相氧化铝与复合工程的各种晶界。具体目标是（1）将LSP引起的压缩残余应力的程度与晶界特征分布和晶粒尺寸相关联，以及（2）识别与高位错密度相关的单个晶界结构。工程专业的学生正在学习陶瓷加工和电子显微镜表征方面的宝贵技能。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Microstructures and mechanical properties of α‐SiC ceramics after high‐temperature laser shock peening

高温激光冲击强化α-SiC陶瓷的显微组织与力学性能

• DOI: 10.1111/jace.18222
• 发表时间: 2021
• 期刊: Journal of the American Ceramic Society
• 影响因子: 3.9
• 作者: Wang, Fei;Chen, Xin;DeLellis, Daniel P.;Krause, Amanda R.;Lu, Yongfeng;Cui, Bai
• 通讯作者: Cui, Bai