Electrochemical Machining Titanium Alloys

Parts with titanium and its alloys are becoming increasingly important in the aerospace industry, and they are usually prepared by electrochemical machining. So their special characters, the passivating film and some corrosive pittings, are becoming widely noticeable in electrochemical machining process. The passivating film tends to form on the machining surface, which makes the machining difficult to proceed, and some corrosive pittings usually appear on the non-machined surface lead to the poor surface quality. This paper focuses on the enhancement of the surface quality in electrochemical machining.The following work has been done in this paper:1. The experimental apparatus is designed and prepared.2. The effect of kinds of electrolyte on the surface quality is investigated, and an optimal electrolyte is obtained;3. The effect of machining parameters, both the concentration of the electrolyte and current density, on the surface quality is finished, and the experiment plan is made using the method of uniform design. Finally the optimal machining parameters are gained;4. The analysis of electric field shows that low current density distributes on the non-machined surface, which leads to poor surface, and it can be eliminated using the additional anode. The electrochemical machining experiments of titanium alloys TC4 indicate the accuracy and reliability of using the additional anode.The experimental results show that an excellent machining surface would be obtained with the additional anode made of platinum in the electrolyte of 10%NaCl+EDTA+4%Na2S2O8 at the current density of 50 A/cm2.