Mechanics-Based Analysis of Small-Scale Surface Generation in Hard-Tool Machining

精密陶瓷部件的最终尺寸和形状通常是通过磨削产生的，这种工艺可以处理这些材料的高强度，但有可能造成微裂纹，导致这些部件的功能失效。将在本研究中调查的替代方案被称为硬刀具加工，其中控制几何切削刃用于加工陶瓷。基于在真实刀具上发现的更真实的大半径切削刃的模型，通过断裂而不是塑性来模拟陶瓷的材料去除机制，以及产生的热量如何影响加工表面层，将由加工动力学和运动学，微观力学，断裂力学和摩擦学的跨学科专家团队考虑。建模将考虑：在微观尺度上预测切屑分离的力学，数值方法，以及与新生成表面完整性相关的合成形貌和应力状态。一个实验程序，以验证建模结果与一个特殊用途的实验装置，以及技术，如扫描电子显微镜，将被用来验证和改进模型。这项研究的主要影响将是通过机械加工来加工陶瓷的基本和更详细的模型，这可以提高生产率并降低高性能陶瓷材料的成本。该模型需要补充实验工作，这些实验工作通常是发展工具和系统所必需的，这些工具和系统需要使高性能陶瓷材料得到更广泛的使用。＊＊＊

9522809 Endres The final size and shape of precision ceramic components are usually generated by grinding, a process that can handle the high strength of these materials, but risks causing micro cracking that can lead to functional failure of these parts. The alternative that will be investigated in this research is termed hard-tool machining, where a controlled geometry cutting edge is used to machine ceramics. Models that are based on the more realistic large radius cutting edges found on real tooling, modeling the material removal mechanism for ceramics by fracture, rather than plasticity, and how the heat generated may affect the machined surface layer will be considered by and interdisciplinary team of experts in machining dynamics and kinematics, micro mechanics, fracture mechanics and tribology. Modeling will consider: mechanics at the micro scale to predict the chip separation, the numerical methods, and the resultant topography and stress state related to the integrity of the newly generated surface. An experimental program to verify the modeling results with a special purpose experimental setup, as well as techniques like scanning electron microscopy, will be used to verify and improve the model. The major impact of this research will be in a fundamental and more detailed model for machining ceramics by machining, that can increase the productivity and reduce the cost of high performance ceramic materials The model is need to supplement the experimental work that would normally be necessary to evolve tools and systems that are needed to enable broader use of high performance ceramic materials. ***