Experimental Investigation On Electrochemical Machining Of ?-TiAl Intermetallic

As one of the most important parts of the aircraft engine, the quality and performance of blade directly relate to the normal operation of the aircraft. In order to reduce the structural weight of the aircraft engine, Advanced mental materials are widely researched in aviation field. ?-TiAl intermetallic compound might replace the nickel-based superalloy because of lightweight ?wear-resisting?high strength?thermal-resisting. Being a non-mechanical metal removal process, ECM provides an economical and effective way for machining heat-resistant, high strength materials into complex shapes which are difficult to machine, so it is the suitable method to process ?-TiAl intermetallic compound. This paper, which focuses on ?-TiAl intermetallic compound ECM, includes the following several aspects.(1) The electrochemical dissolution of ?-TiAl intermetallic compound was removed by studying the anodic polarization curve of ?-TiAl in different electrolyte. Meanwhile, the impact on the pitting behavior of the ?-TiAl intermetallic compound in 10% Na Cl solution at different current density was studied by the single factor experiment of the feed rate of the cathode. The results showed the pitting can be eliminated in high current density.(2) With the study of two types of orthogonal experiment in direct and pulse current electrochemical machining, the effect factors on material removal rate and surface roughness of ?-TiAl intermetallic compound were investigated and analyzed through the use of the grey relational analysis. Finally, the law of the optimized parameter was gained.(3) In order to reduce ? angles on whole curved surface, a new optimization method of tool spatial feeding direction evaluated by the maximum ? angle was proposed. Taking blade complex parts as example, optimization experiment was carried out by using the traditional and new method. The results revealed that the ? angle distribution was more uniform with new optimization method.(4) The experiment on the ?-TiAl intermetallic compound was carried out. Using the optimized processing parameter and cathode spatial feeding direction, blades were machined and achieved the design requirements. The detection results showed that the machining accuracy of the concave and the convex were 0.078 mm and 0.118 mm respectively, and the repeat accuracy was about 0.07 mm.