关键词: 电弧, 放电加工, 电极, 设计, 整体式, 涡轮叶盘, 材料去除率

Abstract: Integral shrouded blisks provide excellent performance for aviation turbine engines and turbo pumps in liquid rocket engines. However, manufacture of these blisks is much more difficult, making it a bottleneck for the production of engines. Electrochemical machining and electric discharge machining are usually adopted for the machining of these parts. The main drawback is poor machining efficiency, resulting in higher cost. For this reason, an electrical arc machining method that uses a grouped electrode to perform parallel roughing of multiple channels under the conditions of high current and long pulse width discharge is proposed. The requirements for grouped electrode design are discussed based on the principle of arc machining. The design workflow of grouped electrode with internal flushing structure is then proposed. The shunt structure of the internal flushing channel is optimized using computational fluid dynamics simulations. The actual performance of the proposed method is verified by a trial production, and the indicators such as material removal rate and electrode wear rate are analyzed. The results show that compared with the previous electrical arc machining method using singular electrode, the material removal rate using the grouped electrode was increased by 62.9%. The total time consumption was reduced to 8.7% of that of the traditional electric discharge machining, benefited from the increase in material removal rate and the reduction in auxiliary time.

Key words: electric arc, electric discharge machining, electrode, design, integral, turbine blade, material removal rate