高温镍基合金涡轮叶片气膜冷却孔电解加工基础试验研究

Fundamental experimental research on electrochemical machining cooling hole of nickle-based superalloy

以探究工艺参数对冷却孔的加工精度和加工效率的影响为主要目的,以高温镍基合金Inconel718为基材进行电解加工气膜冷却孔的基础试验研究。首先利用正交试验初步优化了管电极电解加工冷却孔的参数,其次通过单因素试验进一步研究了电解液入口压力P、加工电压U和电极进给速度f等关键加工参数对加工精度及加工蚀除率的影响,最终确定了最优加工参数组合。试验结果表明:电极进给速度对单边间隙的影响最大,电解液入口压力对单边间隙的影响最小;加工电压对材料蚀除率的影响最大,进给速度对材料蚀除率的影响最小。试验获得的最佳加工参数为:电解液入口压力为0.4 MPa,加工电压为9 V,电极进给速度为0.42 mm/min,在此参数组合下加工出冷却孔的加工精度和加工效率为最优。

Film cooling holes were obtained by electrochemical machining using Inconel718 nickel-based super-alloy which is commonly used for turbine blade of aero-engine. In order to explore the effect of machining parameters on processing accuracy and efficiency, orthogonal tests and single factor experiments were conducted. The parameters of the cooling hole were optimized by orthogonal experiment. The effects of the inlet pressure of electrolyte, processing voltage and electrode feed rate on the single side gap and MRR were analyzed, obtaining an optimal process. The results showed that： the effect of the electrode feed rate on the side gap is the largest while the effect of the inlet pressure on the side gap is the smallest. The effect of the processing voltage on the corrosion rate is the biggest, and the feed rate has the least effect on the removal rate. The optimal parameters were obtained： the machining accuracy and machining efficiency of cooling holes are optimal at the inlet pressure of 0. 4 MPa, processing voltage of 9 V and electrode feed rate of 0. 42 mm/min.