The Investigation Of The Microstructure And Properties Of The AlCuMgLiSc(Ag) Alloy And C_f/AlCuMgLiSc(Ag)Composites

In this study,the AlCuMgLiSc alloys were alloyed with Ag elements.ShortCarbon fiber strengthening composites Cf/AlCuMgLiSc and Cf/AlCuMgLiScAg werefabricated using liquid stirring casting mehthod by adding3Vol.%carbon fiber intoAlCuMgLiSc and AlCuMgLiScAg matrixs.The physical properties,mechanicalproperties and microstructure of different materials were investigated by Archimedesdensity test,immersion test,Vickers hardness testing,tensile testing,optical microscopyanalysis,scanning electron microscopy and other methods.The experimental resultsshow that:The optimal solution treatment process is530℃solution temperature and1hoursolution time for AlCuMgLiSc and AlCuMgLiScAg and525℃solution temperatureand1hour solution time for Cf/AlCuMgLiSc and Cf/AlCuMgLiScAg composites.Four kinds of materials have the same aging process,which is190℃agingtemperature and16hours aging time.Alloying with0.2%Ag to AlCuMgLiSc andCf/AlCuMgLiSc improved the mechanical properties of AlCuMgLiSc alloys andCf/AlCuMgLiSc composite.The addition of0.2%Ag resulted in an increase of thetensile strength,yield strength and micro-yield strength to537MPa,500.6MPa and328.3MPa for AlCuMgLiSc alloy,which increased by3.89%,3.9%and1.7%respectively and559.3MPa,501.3MPa and347MPa for Cf/AlCuMgLiSccomposites,which increased by0.7%,3.1%and3.1%respectively.The addition of3Vol.%carbon fiber caused a increase of tensile strength of Cf/AlCuMgLiSc andCf/AlCuMgLiScAg composites to555.2MPa and559.3MPa,which increased by7.4%and4.2%respectively.And the micro-yield strength reached336.5MPa and347MPa,which increased by4.2%and5.7%respectively.The defects existed in cast microstructure and gas involved in the compositematerial caused by carbon fiber decreased the density and compactness of as castingAlCuMgLiSc(Ag) alloys and Cf/AlCuMgLiSc(Ag) composite.Hot extrusion ofmaterial can increase the density and compactness of the materials.The compactnessof AlCuMgLiSc and AlCuMgLiScAg alloys,as well as Cf/AlCuMgLiSc andCf/AlCuMgLiScAg composites increased by184%,373%,159%,989%respectivelyafter hot extrusion.The micro-yield strength of four kinds of materials showed the same trend as that of yield strength with the heat treatment processes.The materials have the highestmicro-yield strength are at peak aging while both the underaging and overaging candecrease the micro-yield strength.