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DOI number:10.1007/s00170-025-17048-8
Journal:Precision Engineering
Key Words:Refractory high-entropy alloy Electrochemical machining Composite electrolyte Dissolution characteristic Machining morphology
Abstract:Refractory high-entropy alloys (RHEAs), showing excellent mechanical properties at high temperature, are expected to have promising applications in various industries, for instance, the key components of aero engines. On account of high strength and hardness as well as good corrosion resistance, electrochemical machining (ECM) brings in a promising but challenging way to process RHEAs efficiently. In this work, to implement a practicable ECM process for RHEAs, the electrochemical dissolution behavior of a (TiVCr)95W5 RHEA in different pH conditions was investigated using different solutions, namely 10% NaNO3, 10% NaNO3+0.5% HNO3, and 10% NaNO3+0.5% NaOH. The results show that the RHEA exhibits a more significant corrosion tendency, lower resistance, and more uniform dissolution for each refractory element in the 10% NaNO3+0.5% NaOH solution than that in the other two solutions, and the heterogeneous corrosions in interdendritic areas are also eliminated. The effects of OH- ion concentration, cathode feed rate, machining voltage, and duty cycle on the ECM performance of the RHEA were then investigated. Further, a dissolution model for the dissolution behavior of RHEAs during ECM has been established. Besides, an orthogonal experiment was also carried out to optimize the processing parameters, where the best performance was achieved by an electrolyte of 10% NaNO3+0.5% NaOH, a cathode feed rate of 5.4 μm/s, a machining voltage of 23 V, and a pulsed power duty cycle of 30%. Finally, a round hole of 1.224 mm diameter (the standard deviation of diameter is 0.0176mm and the relative error is 2.04%) and a 0.9778×0.9746 mm square hole were successfully machined using ECM (the standard deviation of transverse and longitudinal are 0.0183 and 0.0126 mm respectively), which further verified the feasibility of machining RHEAs using the ECM technique.
Co-author:许海涛,唐文俊,练忠浩,乔宜祥,岳小康
First Author:Juchen Zhang
Indexed by:Journal paper
Correspondence Author:陈顺华
Discipline:Engineering
Document Type:J
Translation or Not:no
Date of Publication:2025-12-06
Included Journals:SCI