Two-Dimensional Cutting of Polycrystalline Diamond and CBN Tools and Dies using a Novel Laser/Waterjet Hybrid Manufacturing Process

本项目的目的是验证以下两个假设：1)在二维切割过程中，激光和水射流的共同作用将导致垂直于切割路径的拉伸应力的发展和沿切割路径的裂纹扩展；2)如果材料的去除机制从热熔蒸发（激光切割）或材料侵蚀（电火花加工）转变为通过裂纹扩展的材料分离，则切口较小；平行墙;与传统加工工艺相比，多晶金刚石和多晶立方氮化硼二维轮廓加工具有更高的切削速度和显著的节能效果。该项目的方法是通过基础断裂力学建模和实验来验证假设，以研究激光加热和水射流淬火的热和化学效应对超硬材料的控制断裂。研究活动的成功完成将导致脆性材料的一种新的加工方法，以及对这一新工艺背后的基本基础的详细了解。这种新型的混合制造工艺将有潜力分别为金属切削和拉丝行业提供高性能的工具和模具。汽车、木工和其他使用合成金刚石工具的行业将从这项研究中受益匪浅。教育和外展成果将包括培训研究生进行先进制造业研究、将研究成果纳入新的课程单元、让代表性不足的群体的本科生参与研究团队，以及通过期刊出版物、会议、行业访问和讲习班传播研究成果。

The objective of this project is to test the following two hypotheses: 1) the combined action of laser and waterjet will result in development of tensile stresses perpendicular to cutting path and propagation of cracks along cutting path during the two-dimensional cutting and 2) if the material removal mechanism were changed from thermal melt and evaporation (laser cutting) or material erosion (electrical discharge machining) to material separation through crack propagation, then smaller kerf; parallel walls; higher cutting speed and substantial energy savings can be attained in the machining of two-dimensional profiles of polycrystalline diamonds and polycrystalline cubic boron nitride over conventional machining processes. The project's approach is to test the hypotheses relies on fundamental fracture mechanics modeling and experiments to investigate controlled fracture of superhard materials due to thermal and chemical effects of laser heating and waterjet quenching.Successful completion of the research activities will lead to a novel machining method for brittle materials along with a detailed understanding of the fundamental underpinnings behind this new process. This novel hybrid manufacturing process will have potential to offer high performance tools and dies for metal cutting and wire drawing industries respectively. Automotive, woodworking and other industries that use synthetic diamond tools would greatly benefit from this research. Education and outreach outcome will include training of graduate students in advanced manufacturing research, assimilation of the research outcomes into new course modules, the involvement of undergraduates from underrepresented groups in the research team and the dissemination of the research results through journal publications, conferences and industry visits and workshops.