Investigation of electrolyte intermittent commutation effects on electrochemical machining

Abstract

ABSTRACT Traditional blade electrochemical machining (ECM) adopts electrolyte unidirectional flow (EUF), resulting in serious accumulation of insoluble byproducts, gas, and Joule heat along the flow path. Here, an electrolyte intermittent commutation flow (EICF) was reported. Blade formed with EICF model was simulated, by comparison with EUF. Exploratory experiments were carried out, and how the time ratio of forward electrolyte flow time (t F) and reverse electrolyte flow time (t R) affects the blade ECM performance was investigated. The manufacturing accuracy and surface roughness depend on t F:t R, and they first improve and then deteriorate, reaching its optimal value at t F:t R = 1:3. Finally, the surface morphology is less affected by the t F:t R, the dissolution morphology exhibits that grain boundary is preferentially susceptible to electrochemical attack, compared with grain. The reason for this corrosion mechanism is that Ti and Nb are more easily enriched at the grain boundaries, while Cr, Fe and Ni are depleted.