Comparative Study of Grain Size and Mechanical Properties of Die-cast and Spray Formed Al-4.5 wt. % Cu Alloys Deposit

An Al-4.5 wt. % Cu alloy was prepared by die casting and spray forming process. The grain size, grain size distribution, porosity of the alloys were measured using optical metallurgical microscope and influence of grain refinement on mechanical properties of Al-4.5 wt. % Cu alloy was investigated in the present paper by performing a tensile test. The optical micrographs of die-cast alloy revealed the coarse equiaxed and dendritic structure, whereas spray formed alloy exhibits finer microstructure with equiaxed grain morphology. The average percentage of porosity in spray formed and die-cast alloy was quantified using image analysis. An evaluation of the YS and UTS of the spray formed alloy inferred excellent YS and UTS compared to its conventional die-cast counterpart. The analysis of the data showed that YS is influenced by the grain size and the distribution of the θ phase (CuAl 2 ).