酒石酸钠对叶片冷却孔电解加工的影响研究

Effect of sodium tartrate on electrochemical machining of blade cooling holes

以航空发动机涡轮叶片常用材料Inconel718高温镍基合金为基材进行气膜冷却孔电解加工试验。基于自行研制的数控电解加工机床系统,通过30组对比试验,分析了在不同浓度硝酸钠电解液中添加2%浓度的酒石酸钠添加剂后对冷却孔加工过程稳定性及加工精度的影响规律。试验结果表明:硝酸钠电解液添加2%浓度的酒石酸钠后,电解加工区域的固态电解产物和加工过程的短路次数明显减少,加工稳定性得到很大改善,同时所加工冷却孔的单边侧面间隙有所减小,酒石酸钠的加入对提高冷却孔加工过程的稳定性有明确而积极的意义,对提高其加工精度也有一定的作用。

Film cooling holes were obtained by electrochemical machining using Inconel718 nickel- based superalloy which is commonly used for turbine blade of aero- engine. 30 experiments were conducted on the developed electrochemcial machining setup. The effect of adding 2% sodium tartrate into the Na NO3 electrolyte with different mass fraction on the stability and dimensional accuracy of the electrochemical machining cooling holes was analyzed. Experiments results demonstrated that adding 2% sodium tartrate into the Na NO3 electrolyte,the solid electrolytic product of electrochemical machining area and process of short- circuit significantly reduced,machining stability had been greatly improved,also the single side gap was smaller,and the size precision was improved,that sodium tartaric acid can effectively improve the electrochemical machining stability and slightly improve the dimensional accuracy of cooling holes.