Finite element analysis and experimental study on electrochemical modification assisted machining of W–Ni–Fe alloy

The traditional cutting process of tungsten heavy alloys (WHAs) suffers from problems including high cutting force, severe tool wear and poor machining quality. In this paper, an electrochemical modification assisted cutting process is proposed to reduce the cutting force. This is achieved by utilizing the selective electrochemical etching property of the WHA in an alkaline sodium carbonate solution, which decreases the stiffness of the cutting layer. A finite element simulation model, which considered the microstructure of two phases, was established to reveal the material removal mechanism before and after electrochemical modification. The simulation clarifies the key factors of the magnitude and fluctuation of the cutting force and explains the mechanism of the effect of electrochemical modification on the cutting force. Cutting experiments on the 95W-3.5Ni-1.5Fe alloy revealed that, compared to traditional cutting, electrochemical modification assisted cutting significantly reduced cutting forces, from 3.034 N to 0.112 N for the PCD tool and from 5.443 N to 0.106 N for the TiAlN-coated carbide tool. Additionally, it effectively suppressed tool wear on both the rake and flank faces and improved surface quality by reducing the surface roughness Sa from 1.667 μm to 0.947 μm and the PV value from 12.713 μm to 10.014 μm. The electrochemical modification assisted cutting process proposed in this paper can potentially solve the WHA machining challenges.