The influence of aging treatment on the tensile and notched tensile properties of the advanced spray casting aluminum alloys of 7XXX series

摘要

Tensile and notched tensile properties of spray deposited SS70 aluminum alloy with Zr and Mn as dispersoid forming elements have been studied as a function of aging temperature. In spite of the high alloy contents (11,3 wt % Zn, 2.24%Mg, 1.07%Cu,0.01%Mn, 0.22%Zr, 0.04%Fe, 0.03%Si) second phases have been refined. The grain size has also been refined during the spray casting process. The effects of this refined microstructure show that SS70 has a clear strength advantage of 25 to 30% over the 7075 aluminum alloy. In association with this strength an increase in ductility of over 30% were obtained at aging temperatures of 120°C and 150°C.Results of notched tensile experiments also show that high toughness values are achievable despite of the increase in the strength at these aging temperatures. The toughness is not as high as those of the equivalent strength powder alloys. Compared topowder process, spray casting method does not have size limitation and the cost of the product is greatly reduced. The results of this study show that SS70 is a suitable candidate alloy for aerospace components with high strength and toughness.