High-efficiency machining of titanium alloys small and deep holes with multivariable adaptive control system

A multi-electrode machining method guaranteed by a multivariate adaptive control system was developed to improving stability, efficiency, and reducing work-piece surface burning in electrical discharge machining (EDM) deep holes of titanium alloys. It was found that as current increased exceeding the current-carrying capacity of an electrode , machining state deteriorated quickly to halt the machining. In this case, it was proposed to increase the number of electrodes to enlarge bearing capacity of current so as to using a large current for high machining efficiency. Meanwhile, a multivariate adaptive control system was applied to keep processes fast and stable of machining titanium alloys. Experimental results demonstrated that the multi-electrode driven by the adaptive control system was very effective for machining titanium alloy. When 7 graphite electrodes were used to process titanium alloy with a thickness of 40mm at the same time, the single-hole machining time was 1.27h, and the electrode loss was only 17.81%.