Microstructure and Mechanical Properties of P/M Al-Fe-Cr-Ti-Mm (Mm: Misch Metal) and Al-V-Fe-Mm Alloys

Abstract

Al-Fe-Cr-Ti and Al-V-Fe alloys prepared by the powder metallurgy (P/M) process have high strength exceeding 600 MPa, high-elevated temperature strength exceeding 300 MPa after holding for 100 hours at 573 K and more excellent wear resistance than commercial A390 aluminum alloy. In this work mechanical properties of the P/M Al₉₃Fe₃Cr₂Ti₂ and Al₉₄V₄Fe₂ alloys were found to be improved by the addition of misch metal (Mm). P/M Al₉₂Fe₃Cr₂Ti₂Mm₁ alloys containing quasicrystalline phase were prepared by extrusion of argon gas atomized powders at 673 K, where the atomized powders sieved into the sizes smaller than 75μm were used. The P/M Al₉₂Fe₃Cr₂Ti₂Mm₁ alloy has a mixed structure consisting of Al, quasicrystal and compounds phases and exhibits good mechanical properties as follows: ultimate tensile strength (σ_UTS) of 680±13 MPa, 0.2% proof strength (σ_0.2) of 670±10 MPa, plastic elongation (εP) of 0.3±0.1%, Young's modulus (E) of 91±3 GPa and Vickers hardness (Hv) of 230±3, respectively, at room temperature, and alas of 347±5 MPa, σ_0.2 of 315±3 MPa and εP of 1.8±0.3%, respectively, after holding for 100 hours at 573 K.