Control of Fracture Damage in Precision Machining of Ceramics

该项目将研究无损伤超精密加工 先进陶瓷材料的工艺。 我们的目标是 更好地理解材料去除过程， 发生在陶瓷的纳米级研磨中，并最终 能够在加工过程中控制磨削损伤的产生。的 研究计划包括扩展延性区磨削模型 包括增韧陶瓷，并定义磨削加工 这些材料所需的参数。 进一步修改 研磨工艺采用工程化的 陶瓷表面上的化学机械效应将得到发展， 通过控制表面韧化。 这项研究的一个目标是 开发实时声发射反馈系统， 测量和控制过程中的磨削损伤。 通过 初步研究表明，声发射对 已建立材料去除工艺。 理解 敏感性基础及其与地下的关系 裂缝的产生将指导有效控制的开发 战略 预计作为本研究的直接结果：（1） 模型的延性制度磨削，开发的主要 调查员，将扩大到包括坚韧，先进的陶瓷 材料;（2）陶瓷加工中的化学机械效应 将研究它们是否有可能改变 陶瓷的表面性能，从而提高可加工性 候选陶瓷材料;和（3）再生产生的声学 排放信号将分析在这些基础研究 弹性波及其与磨削诱发次表层的关系 损害

The project will study damage-free ultraprecision machining processes on advanced ceramic materials. The goal is to generate an improved understanding of the material-removal processes that occur in nanometer-scale grinding of ceramics, and ultimately to be able to control grinding damage generation in-process. The research plan includes extending the ductile-regime grinding model to include toughened ceramics, and defining grinding machining parameters required for these materials. Further modification of the grinding process by the introduction of engineered chemomechanical effects on the ceramic surface will be developed, through controlled surface toughening. A goal of this research is to develop a real-time acoustic emissions feedback system to measure and control grinding damage in-process. Through preliminary research, the sensitivity of acoustic emissions to material removal processes has been established. Understanding the basis of that sensitivity and its relationship to subsurface fracture generation will guide development of an effective control strategy. It is expected that as a direct result of this research: (1) models for ductile-regime grinding, developed by the principal investigator, will be extended to include tough, advanced ceramic materials; (2) chemomechanical effects in machining of ceramics will be studied with regard to their potential for altering the surface properties of ceramics, thereby enhancing the machinability of candidate ceramic materials; and (3) fracture-generated acoustic emissions signals will be analyzed in a basic study of the these elastic waves and their relationship to grinding-induced subsurface damage.