The surface tribological properties of 7075 aluminum alloy by HS-WEDM

To investigate the friction resistance of the surface of 7075 aluminum alloy, HS-WEDM(High-speed Wire Electrical Discharge Machining) process was used and the friction properties and surface roughness of 7075 aluminum surface are analyzed. The effects of pulse on-time, pulse off-time, pulse current and frequency tracking on performance have been investigated. Using the HS-WEDM technology, the recast layers were fabricated spontaneously on 7075 aluminum alloy surface. To analyze the recast layers thickness of 7075 aluminum alloy surface, laser confocal microscopy was used to observe the microstructure morphology of reaction film. The friction properties of the recast surface were analyzed by RETC micro friction under dry sliding conditions. Results show that the recast layer surface after HS-WEDM processing has good stability and durability. Moreover, the average friction coefficient is decreased 70% compared with substrate, showing superior excellent friction performance and mechanical properties.