电火花辅助铣削钛合金的材料去除机制及其工艺优化

The project aims at the extensive demand of titanium alloy in aviation and medical fields. In order to solve the problems of low processing efficiency and poor processing quality in titanium alloy machining, the idea of surface modification of workpiece to reduce cutting force is put forward, and a novel tool is innovated to form a new electrical discharge assisted milling (EDAM) method. The formation and evolution mechanism of the deterioration layer on the surface of materials after discharge ablation and the material removal mechanism under the interaction of compound energy fields are two key scientific issues. The formation and evolution of the deterioration layer on the workpiece surface after discharge ablation milling and the mechanism of material removal under the action of compound energy field in electrical discharge assisted will be studied to realize the active control of the characteristics of the surface deteriorated layer and the efficient removal of materials. The modeling methods of material molecular dynamics and heat transfer theory during discharge will be studied to reveal the interaction mechanism between discharge temperature field and workpiece materials, to explore the evolution mechanism of surface deterioration layer under compound temperature field, and to formulate the active control strategy of surface deterioration layer. The formation mechanism of the interaction coupling of multi-spatio-temporal compound energy field will be studied to reveal the material removal mechanism and surface formation mechanism under the interaction coupling of compound energy field. Aiming at improving the processing efficiency and surface quality, the discharge assisted milling process will be optimized comprehensively to achieve high efficiency and precision machining of titanium alloy.

项目面向钛合金在航空和医疗等重要领域的广泛需求，针对钛合金加工中存在的加工效率低、加工质量差等突出问题，提出对待加工材料表面改性以降低切削载荷的思路，创新设计刀具，形成电火花辅助铣削新方法。围绕放电腐蚀后表面变性层的形成及演化机制和复合能场交互耦合作用下的材料去除机理2个关键科学问题，开展电火花辅助铣削放电蚀除后材料表面变性层的形成及演化机制、复合能场作用下的材料去除机理研究，实现表面变性层特征的主动控制及材料高效去除。重点研究放电过程中材料分子动力学和工件材料传热学建模方法，揭示放电温度场与工件材料之间的相互作用机制，探明复合温度场下表面变性层的形性演变机制，制定表面变性层的主动控制策略；研究多时空复合能场交互耦合作用的形成机制，揭示复合能场交互耦合作用下的材料去除机理和表面创成机制；以提高加工效率和加工表面质量为目标，对放电辅助铣削工艺进行综合优化，实现钛合金材料的高效精密加工。

项目面向钛合金在航空和医疗等重要领域的广泛需求，针对钛合金加工中存在的加工效率低、加工质量差等突出问题，提出对待加工材料表面改性以降低切削载荷的思路，创新设计刀具，形成电火花辅助铣削的新方法。采用实验、有限元仿真及数学建模的方法，对电火花辅助后工件温度场的时空演变规律、多复合能场下钛合金材料的去除机理以及放电辅助铣削工艺的综合优化进行了深入研究。项目发明了多种电火花辅助铣削高效切削专用刀具，用多种有限元仿真技术揭示了电火花辅助铣削加工前后工件的能场演变规律，探明了不同放电能量的温度分布及优选方法；构建了电火花辅助铣削加工的热-力耦合切削仿真模型，揭示了铣削过程中应力、温度及切削力的变化规律；提出了复合能场切削的有限体积数值建模方法，精准地预测电火花辅助铣削的切削力；最终基于多数学方法的多参数工艺优化方案，实现钛合金的高效精密加工。初代的超声-电火花辅助切削多用途机床已经制作完成。项目共发表论文13篇，其中SCI 12篇，CSCD 1篇，获国家发明专利授权3项、实用新型专利授权11项。以该项目依托培养1名研究生毕业和7名研究生在读，本科生若干名，组织国际学术会议2次。本项目通过三年的研究工作，已完成项目的计划内容和目标。