Study on the Friction and Wear Performance of 7075-T6 Aluminum Alloy under Electro Assisted Forming

In order to address the surface quality and friction-wear issues of 7075-T6 aluminum alloy thin sheet in stamping forming， Electro Assisted Forming (EAF) technology was introduced into the stamping process.The effects of current densities ranging from 0 to 20 A/mm2 on the surface hardness， surface roughness and friction-wear behavior of the aluminum alloy thin sheet were studied and compared with the results of Hot Stamping (HS).A friction testing machine for EAF was used to simulate the forming process， and infrared thermography， Vickers hardness tester，shape measurement microscope，X-ray diffraction (XRD)，scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) were employed to observe and analyze the temperature， surface hardness， surface roughness， friction coefficient and wear behavior of the specimens.Results showed that， within the range of 0 to 16 A/mm2， the surface hardness of the EAF-processed specimens was higher and the surface roughness was lower than that of the HS-processed specimens at the same temperature.The enhancement of surface properties by electroplasticity at low current densities was attributed to the inhibition of the η′ metastable phase transition to the stable η phase.At high current densities， the Joule heat generated by electroplasticity caused significant softening of the thin sheet.The friction coefficient of the EAF specimens initially decreased and then increased with the rise in current density， reaching a minimum around 12 A/mm2.At this point， the friction coefficient of the EAF specimens was reduced by more than 10%compared to the HS specimens.After being processed by EAF at current densities ranging from 0 to 16 A/mm2， the specimens showed a lower wear rate， and a denser oxide layer was more easily formed on the surface， resulting in improved friction and wear resistance.