| 7090Al/SiCp composites were prepared by spray co-deposition processing with moving crucible.After hot extrusion,solution and aging , the structure and properties of composite material were studied, the main findings are as follows:(1) High Zn content 7090/SiCp composite materials were prepared by co-deposition, the features of composite materials have small grain,symmetrical,small segregation and high density structure.(2) The microstructure of the deposited and extruded composite materials were studied,the results shows that the extruded composite material have a lot of the second phase particles,mainly CuAl2 orAl2CuMg and small amount of Fe intermetallic compounds and single-Si phase, These particle phases are saturated precipitation.(3) DSC analysis results showed that the extruded composite form supersaturated solid solution when it solute at above 476.4℃,these provide a theoretical basis for rule of solution.(4) Compared with the microstructure of the single solution and the double solution and the mechanical property of the two solution,the results show that 7090/SiCp composite get the top aging when the composite have dealed with 450℃/3h+500℃/3h +120℃/18h,and the composite mechanical property increase obviously compared the extruded, the ultimate tensile strength of the composite can reach over 750Mpa,elongation at about 2%.(5) Observing and analyzing of TEM show that 7090/SiCp precipitate G.P.area andη′phase with single aging, intensified effect is in best condition. the strength decrease obviously with double aging because precipitated phases become coarse and precipitateηphase when temperature increase. |
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