EXTRUSION FORMING OF RAPIDLY SOLIDIFIED AlCrYZr ALUMINUM ALLOYS AND THEIR MICROSTRUCTURES AND TENSILE PROPERTIES

An AlCrYZr aluminum alloy was made up by adding alloy element yttrium. By using of optical microscopy, x-ray diffration, transsion electron microscopy, scanning eletron microscopy and tensile test, extrusion forming process of rapidly solidified powder of AlCrYZr aluminum alloy was studied and its effect on microstrutures and mechanical properties of the alloys were investigated. The results show, the main second phase of the testing alloy are Al₂₀Cr₂Y(Cubic, a=1.44 nm) and DO₂₃Al₃Zr,and to increase extrusion ratio and lower extrusion temperature during extrusion forming is benificial for improving binding state of powder, obtaining Ll₂Al₃Zr precipitated particle and making Al₂₀Cr₂Y particle fine and then getting dynamic recovery microstructure in the aluminum matrix, therefore, the alloy prepared by using a suitable consolidation roue has good strength and plasticity at room temperature and evelated temperature.