Three-dimensional simulation and experimental investigation of electrolyte jet machining with the inclined nozzle

摘要

Electrolyte jet machining (EJM) is an innovative form of electrochemical machining (ECM) with excellent machining flexibility and accuracy. Recently, the nozzle inclination is introduced into EJM to further expand its machinability. In this work, to clearly reveal the mechanism behind this EJM process, a three-dimensional (3-D) multiphysics model of the stationary EJM process accounting for two-phase flow field and electric field was developed for the first time and experiments were also performed for validation. With the inclined nozzle, the distribution of flow velocity and thickness of electrolyte film around the jet exhibits uneven, thus resulting in non-circular hydraulic jump and non-axisymmetric anodic current density distribution, respectively. Besides, the effects of nozzle inclination angle and electrolyte ejecting flow velocity were investigated. Larger inclination angle leads to increased asymmetry of flow velocity and current density distribution, which results in more seriously non-circular hydraulic jump and asymmetric machined dimple shape. The electrolyte ejecting flow velocity affects the jet shape and current density distribution that eventually influences the machined results with the inclined nozzle, but this effect does not exist with the conventional vertical nozzle. Moreover, this work was extended to the translating EJM process to study the effect of nozzle translating direction with the inclined nozzle. It is demonstrated that through selecting translating directions, grooves with different shapes and surface finish can be machined even using a certain nozzle inclination. The mechanism for these phenomena was clarified by simulation, paving the way for design of the EJM process with the inclined nozzle.