Fabrication of Metallic Glass Layers on Al Alloys with Improved Corrosion Resistance and Micro-Hardness by Pulsed Electrical Discharge Treatment

Pulsed electrical discharge (PED) is a method that has been employed to fabricate metallic glass (MG) layers on Al-Cu-Mg-(Zn) alloys. Abnormal Al and Cu element segregation has been found on the alloys vitrified surfaces after PED treatment. Surface element evaporation was found and proven to be the main reason for such significant segregation. Benefits to the evaporation of the non-corrosion resisting elements in the MG layers, the corrosion resistance, and the surface hardness of Al-Cu-Mg-Zn alloys have been greatly improved. The average corrosion rates of Al-Cu-Mg-Zn alloys with MG layers were reduced to about 2% of that without MG layers. Additionally, the surface hardness of Al-Cu-Mg-Zn alloys with MG layers was increased to 537.173 (±7) HV0.1. PED treatment is a promising way to synthesize MG layers with controllable element proportions and distributions for wear- and corrosion-resistant coatings on traditional Al-Cu-Mg-Zn alloys.