硬质合金材料超声辅助电火花磨削加工技术及机理研究

Commented carbide is widely applied in modern industry , defense-related technology and industry etc for its good mechanical properties, but its hard machinability of commented carbide is crucial for its application. Many machining methods are used in the production of commented carbide. However, all have both advantages and disadvantages. Based on the up to date development of the machining technology for commented carbide, this dissertation presents research on processing mechanism of commented carbide by ultrasonic vibration assisted electrical discharge machining and grinding. The research content include the design of the machine tool of ultrasonic vibration assisted electrical discharge machining and grinding, to propose the physical models of the material removal in work ultrasonic vibration assisted electrical discharge, to propose the physical models of the material removal in work lateral or axial ultrasonic vibration assisted electrical discharge machining and grinding, based on the theory of brittle-ductile transition, to analyze the material removal mechanism in work ultrasonic vibration electrical discharge machining and grinding, to propose the mathematical model of grinding force and the critical grinding depth, the combined machining experiments are conducted to test and verify all theories. The combined machining is practical technology for processing hard-brittle materials to high efficient and high roughness. The machining mechanism may provide the theoretic foundation for molding machining of hard-brittle materials.

硬质合金材料具有良好的机械性能而在现代工业、国防科技等领域得到广泛的应用，使其作为高性能的模具材料应用于许多高精密模具，但材料的硬脆特性造成加工成型非常困难，一定程度上制约了其推广应用。硬质合金常用的加工方法很多，各有利弊。本项目结合目前常用的加工方法，在已有研究成果的基础上提出了硬质合金的超声超声辅助电火花磨削加工技术及机理研究课题。本课题的主要内容包括超声辅助电火花磨削加工实验设备的改造实现、硬质合金超声振动辅助下火花放电对材料蚀除热物理模型的建立、轴向和切向附加超声振动的磨削加工材料去除数学模型的建立、基于塑-脆变形理论的超声振动辅助电火花磨削加工磨削力理论模型及临界切削深度模型的建立、样本加工实验及加工结果分析。超声辅助电火花磨削加工实现了硬质合金的高效高精度加工，通过模型的建立及实验的验证，复合加工机理进行了深入的研究分析，为硬脆材料的成型加工提供理论依据。