Influence of processing methods of die casting and spray forming of Al-5wt.% Zn alloy on microstructure and mechanical properties

Al-5 wt.% Zn alloy is produced through the die casting and spray atomization process. The spray atomization process is carried out for a spray height of 325 mm from the substrate. The grain size of as-cast and spray-atomized Al-5 wt.% Zn alloys is reported as 95 µm and 178 µm, respectively. The microstructure of the as-cast Al-5 wt.% Zn alloy revealed a dendritic structure, whereas the same alloy of the spray-atomized deposit exhibited equiaxed grains. The porosity of as-cast and spray-atomized deposits are analyzed from the image analysis and are obtained as 4.8 and 3.15%, respectively. The micro Vickers hardness of as-cast Al-5 wt.% Zn alloys is 22.53 HV1, and the spray-atomized Al-5 wt.% Zn alloy deposit is reported as 28.25 HV1. The 0.2% yield and ultimate tensile strength of as-cast and spray-atomized Al-5 wt.% Zn alloy were calculated by conducting the quasistatic tensile test. The 0.2% yield strengths of as-cast and spray-formed deposits are reported as 58 MPa and 61 MPa, respectively. The ultimate strength of an as-cast Al-5 wt.% Zn alloy is found to be observed as 93 MPa, and the ultimate tensile strength of the same spray-formed deposit is 122 MPa.