A Comparative Study on the Effect of Ultrasonic Vibration on Aluminum Surface Properties in Electrical Discharge Alloying

In this paper, considering the importance of surface integrity, effect of ultrasonic vibration of the Monel 400 electrode with a frequency of 20 kHz on the output parameters of the aluminum surface properties (surface hardness and wear resistance, thickness of the surface layer, the depth of copper and nickel diffusion to the aluminum surface and surface roughness) by the method of electrical discharge surface alloying has been studied. Based on the results of the SEM images, the surface layer thickness in the combination of ultrasonic vibration with the electrical discharge alloying process is more than the non-vibration mode. Therefore, increasing the thickness of this layer increases the surface wear resistance. Also, the microhardness test results show that surface hardness of the aluminum has increased to 450 vickers after the combination of ultrasonic vibration with the alloying process. According to the results of EDX analysis, the diffusion depth of alloying elements (copper and nickel) is higher in ultrasonic electrical discharge alloying, So that the surface layer thickness is up to 50 microns. Also, based on the results of surface roughness measuring, ultrasonic vibrations reduce the aluminum surface roughness after surface alloying.