Bulk Al–Al_3Zr composite prepared by mechanical alloying and hot extrusion for high-temperature applications  

作　　者：E.Pourkhorshid M.H.Enayati S.Sabooni F.Karimzadeh M.H.Paydar 

机构地区：[1]Department of Materials Engineering, Isfahan University of Technology [2]Department of Materials Science and Engineering, School of Engineering, Shiraz University

出　　处：《International Journal of Minerals,Metallurgy and Materials》2017年第8期937-942,共6页矿物冶金与材料学报（英文版）

摘　　要：Bulk Al/Al_3Zr composite was prepared by a combination of mechanical alloying(MA) and hot extrusion processes. Elemental Al and Zr powders were milled for up to 10 h and heat treated at 600℃ for 1 h to form stable Al_3Zr. The prepared Al_3Zr powder was then mixed with the pure Al powder to produce an Al–Al_3Zr composite. The composite powder was finally consolidated by hot extrusion at 550℃. The mechanical properties of consolidated samples were evaluated by hardness and tension tests at room and elevated temperatures. The results show that annealing of the 10-h-milled powder at 600℃ for 1 h led to the formation of a stable Al_3Zr phase. Differential scanning calorimetry(DSC) results confirmed that the formation of Al_3Zr began with the nucleation of a metastable phase, which subsequently transformed to the stable tetragonal Al_3Zr structure. The tension yield strength of the Al-10wt%Al_3Zr composite was determined to be 103 MPa, which is approximately twice that for pure Al(53 MPa). The yield stress of the Al/Al_3Zr composite at 300℃ is just 10% lower than that at room temperature, which demonstrates the strong potential for the prepared composite to be used in high-temperature structural applications.Bulk Al/Al_3Zr composite was prepared by a combination of mechanical alloying(MA) and hot extrusion processes. Elemental Al and Zr powders were milled for up to 10 h and heat treated at 600℃ for 1 h to form stable Al_3Zr. The prepared Al_3Zr powder was then mixed with the pure Al powder to produce an Al–Al_3Zr composite. The composite powder was finally consolidated by hot extrusion at 550℃. The mechanical properties of consolidated samples were evaluated by hardness and tension tests at room and elevated temperatures. The results show that annealing of the 10-h-milled powder at 600℃ for 1 h led to the formation of a stable Al_3Zr phase. Differential scanning calorimetry(DSC) results confirmed that the formation of Al_3Zr began with the nucleation of a metastable phase, which subsequently transformed to the stable tetragonal Al_3Zr structure. The tension yield strength of the Al-10wt%Al_3Zr composite was determined to be 103 MPa, which is approximately twice that for pure Al(53 MPa). The yield stress of the Al/Al_3Zr composite at 300℃ is just 10% lower than that at room temperature, which demonstrates the strong potential for the prepared composite to be used in high-temperature structural applications.

关 键 词：aluminum matrix nanocomposites mechanical ALLOYING hot EXTRUSION ALUMINIDES powder METALLURGY 

分 类 号：TB333[一般工业技术—材料科学与工程]