Microstructure and mechanical properties of spray co-deposited Al–8.9 wt.% Si–3.2 wt.% Cu–0.9 wt.% Fe + (Al–3 wt.% Mn–4 wt.% Si)p composite

The microstructure and the tensile properties of an spray co-deposited Al–8.9 wt.% Si–3.2 wt.% Cu–0.9 wt.% Fe + (Al–3 wt.% Mn–4 wt.% Si)p composite was investigated after extrusion and heat treatment. The composition of the AlMnSip alloy was selected aiming to improve the formation of α-Al(Fe,Mn)Si instead of β-Al(Fe,Mn)Si intermetallic. The spray formed deposits were extruded at 623 K and heat treated to peak aged (T6) condition. Room temperature tensile tests of the spray formed and extruded/heat treated alloy showed significant increase of elongation to fracture when compared with the values observed for the as-spray formed deposits, >10% and <4%, respectively. This result can be ascribed to the porosity elimination promoted by the extrusion process and to the lower aspect ratio of the silicon and intermetallic particles. Moreover, the spray formed and extruded, T6 heat-treated samples showed significant increase of the ultimate strength without significant loss of the elongation values.