Abstract:The effect of rotational speed in the friction surfacing of nickel-aluminide reinforced Al-Zn-Mg-Cu alloy matrix composite on commercially pure aluminum was investigated. The nickel-aluminide reinforcement was fabricated by in-situ methods based on adding nickel powders to Al-Zn-Mg-Cu alloy melt during the semi-solid casting process. The findings showed that an increase in the rotational speed from 600 to 1000 r/min raised the coating efficiency from 65% to 76%. Besides, there was no significant difference between coating efficiencies in the coating with and without nickel-aluminide. The outcomes showed that if the coating was applied at a rotational speed of 1000 r/min, a traverse speed of 100 mm/min, and an axial feeding rate of 125 mm/min, the hardness and shear strength of the substrate increased by up to 225% and 195%, respectively. But the wear rate of the substrate dropped by 75%. Although the hardness of the coating containing nickel-aluminide increases by up to 32% compared to the coating without nickel-aluminide, nickel-aluminide does not affect the thermal stability of the coating.

Key words: nickel-aluminide; aluminum matrix composite; friction surfacing; wear resistance