Research On Group Holes Machining By Ultrasonic-Assisted Through-Mask Electrochemical Machining

High-quality hole-array machining of titanium alloys,especially those employed in aerospace thinwalled components,remains a challenge.Electrochemical machining(ECM)is considered the most lucrative due to its wide processing range,high surface quality,and excellent productivity.One of the possible solutions to machine high-quality hole-array is a combined application of the through-mask electrochemical machining(TMECM)and ultrasonic cavitation technique(UCT),which coupling requires the comprehensive analysis of experimental trends of basic parameters controlling both electrolysis and ultrasonic cavitation.In this study,we propose a customized clamping device for the ultrasonic-assisted TMECM,which makes possible a straightforward,direct generation of ultrasonic waves into the electrolyte.Then,trends of such parameters as the ultrasonic frequency and power,electrolyte temperature and pressure are investigated experimentally for the TC4 titanium alloy taken as an example.This paper has carried on the exploration to combine the TMECM and ultrasonic cavitation technique,The specific research contents are as follows:1.A customized set-up was designed for the proposed ultrasonic-assisted TMECM with the option of UCT optimization,which transfers UCT to the electrolyte channel,resulting in the cavitation in the electrolyte and effective electrolysis.It is Safety,high efficiency,light weight and easy operation.2.By the numerical solution of the equation describing the cavitation bubble wall oscillation under the action of ultrasonic waves,six parameters of the ultrasound-assisted TMECM were optimized by their positive influence on the electrolysis reaction and ultrasonic cavitation.These parameters included the ultrasound frequency and power,electrolyte pressure,temperature,viscosity and surface tension coefficients.3.According to a large number of experiments,it is proved that,for ultrasonic-assisted TMECM,the optimal electrolyte temperature was found to be 45°C,while the optimal range of electrolyte pressure was between 0.3 and 0.4 MPa,the ultrasonic cavitation intensity increased as the ultrasonic frequency decreased and the ultrasonic power increased.4.Using these optimization parameters,a proper machining performance was obtained in producing apertures in TC4 titanium alloy via ultrasonic-assisted TMECM,namely,the average conicity angle can be reached to 5° and maximum roundness error is less than 15 μm.The experimental results demonstrate the feasibility of the proposed ultrasound-assisted TMECM setup and optimization of its parameters.