短电弧铣削工具电极材料的放电性能研究

Research for discharge performance of electrode materials by short arc milling

镍基高温合金（GH4169）高温下具有较好的热稳定性、屈服强度高、塑性好的特点,并有较好的焊接性能、较高的耐蚀性和抗氧化性能,在-196~700℃很宽的温度范围内组织性能稳定。用不同电源放电参数与不同电极材料进行实验加工,观察加工效率、工件表面粗糙度、电极损耗、工件表面完整性、工件表面显微结构、工件表面化学成分。实验表明：短电弧加工中,相同加工条件下工具电极的相对质量损耗为铝〉碳钢〉紫铜〉石墨;低电压加工时紫铜电极的损耗率是石墨电极损耗率的7倍,增大加工电压紫铜电极损耗比石墨电极损耗高15~20倍;短电弧铣削加工后,工件表面存在熔滴、凹坑、裂缝和再铸层;短电弧铣削加工中,工具电极材料中元素会向工件里渗透,工件上的元素会向工具电极渗透。

Nickel -based superalloy （GH4169） have wide application in many industries due to their good thermal sta- bility, high yield strength, good plasticity, and has good welding performance, high corrosion resistance and oxidation resistance under high temperature. Observe material removal efficiency, surface roughness of the workpiece, electrode loss, workpiece surface integrity, surface microstructure, chemical composition of the workpiece surface at different power discharge parameters and different electrode materials. Experimental re- suits show： short arc machining, relative mass loss under the same machining condition is aluminum elec- trode, carbon steel, copper, graphite; the loss rate of the copper electrode is 7 times of graphite electrode loss under low voltage and increasing machining voltage copper electrode loss is 15 -20 times of graphite e- lectrode loss. Droplet, curve, crack, recast layer just exist in the workpiece surface after the short arc mill- ing process. The elements in the electrode material will penetrate into the workpiece, and the elements on the workDiece can nenetrate into the electrode in the short arc millin~ nrocess.