Effect of hafnium addition on wear resistance of zinc-aluminum 5 alloy: A three-dimensional presentation

ZAMAK 5 alloy is known to solidify in a large grain dendritic structure, which negatively affects its mechanical properties and surface quality. It is therefore of prime importance to reduce its grain size in order to overcome these drawbacks. In this paper, the effect of addition of hafnium (Hf) on the microstructural and mechanical characteristics of ZAMAK 5 alloy has been investigated. An amount of 0.10 wt.% Hf was introduced to the starting alloy using the well-established microalloying technique. The microstructural examination revealed that addition of Hf transformed the large grained dendrites into fine grains, which turned to increase its hardness number by 2.5% and slightly enhance its both yield and fracture stresses. The wear resistance was determined using a pin-on-disc test at different loads, speeds and time periods and the mass loss results of both alloys, before and after Hf addition, were compared with each other. The results indicated that ZAMAK 5 possesses better per