Impact of Surface Alloying of Nickel on Microstructure, Hardness and Wear on Aluminium-12%Silicon Alloy

摘要

An investigation was carried out to determine the effect of nickel on the microstructure, hardness and wear behaviour of surface alloying on aluminium-12%silicon alloy. The heat source utilized for modifying the surface was gas tungsten arc. Two hundred-micrometre-thick Ni-P coating was pre-deposited using electroless process on the aluminium-12%silicon alloy substrate. The surface alloying process was performed on the coated surface. By using microhardness tester and pin-on-disc wear testing machine, the hardness and wear rate of the modified layer were calculated, respectively. A refined grain structure was observed with the fusion of Ni in the alloyed layer. That was attributed to the rate of cooling in the modified layer. As a result of nickel addition, the hardness was improved and wear rate was found to decrease.