Problems and Solutions in Scanning Electrochemical Machining of Titanium Alloys

摘要

Titanium alloy, known as a difficult-to-cut material, has high specific strength and is widely used in industrial fields. Electrochemical machining (ECM) is considered to be a good choice for machining of difficult-to-cut materials since ECM has the features of non-contact machining, high removal rate and no tool wear. However, it was found that when the tool electrode is scanned at a constant speed over the titanium alloy workpiece, the machined surface becomes uneven and the machining amount decreases along the scanning direction. As a result of experimentally investigating this cause, it was found that the longer the time in the low current density region was, the more uneven machining was carried out. Therefore, in order to reduce the time in the low current density region, a tool with a smaller electrolyte solution region was designed and prepared. By the scanning ECM with the newly designed tool, the scanning ECM of titanium alloy with a uniform depth was realized. Also, the passive film formation on the surface of titanium alloy and its influence on the ECM characteristics were investigated and discussed.