Effect of cutting parameters on the corrosion resistance of 7A04 aluminum alloy in high speed cutting

Abstract

This work aims to explore the effect of cutting parameters on the corrosion resistance of 7A04 aluminum alloy in high speed cutting. First, 7A04 aluminum alloy samples are subjected to short-range solution treatment under 470 °C/1 h and 490 °C/20 min, followed by double-stage aging treatment under 120 °C/3 h + 160 °C/3 h. After heat treatment, the samples are experimentally cut at high speed for single factors to investigate how cutting parameters affect the EIS, polarization curve, and corrosion morphology of 7A04 aluminum alloy in high speed cutting. The results show that for 7A04 aluminum alloy treated by solution treatment 470 °C/1 h, cutting speed 1400–1550 m/min, cutting depth 1.5–2.0 mm and feed rate 0.10–0.12 mm/tooth can yield better corrosion resistance with larger capacitance arc radius, more positive Ecorr, smaller Icorr and R, larger Rp, and fewer corrosion products. For 7A04 aluminum alloy treated by solution treatment 490 °C/20 min, cutting speed 1550–1700 m/min, cutting depth 1.5 mm and feed rate 0.12 mm/tooth can yield better corrosion resistance with larger capacitance arc radius, more positive Ecorr, smaller Icorr and R, larger Rp, and fewer corrosion products. Machined surface with more surface scratches correspond to more corrosion products, whereas adhesive chips and pits are less relevant with corrosion products. EDS analysis reveals that the corrosion products are primarily Al(OH)3 insolubles. Under the same cutting parameters, 7A04 aluminum alloy treated by solution treatment 490 °C/20 min is more corrosion resistant.