Microstructure and mechanical properties of P/M Al-V-Fe and Al-Fe-M-Ti (M = V, Cr, Mn) alloys containing dispersed quasicrystalline particles

By using the conventional powder metallurgy technique, P/M Al-V-Fe and Al-Fe-M-Ti (M = V, Cr, Mn) alloys with a diameter of 8 mm and a length of 300 mm were prepared by extrusion of the atomized powders at an extrusion ratio of 10 and extrusion temperatures (Te) of 623, 673 and 723 K. The structure of the P/M Al94V4Fe2 alloys is identified as fee-Al (Al) + icosahedral quasicrystal (Q.C.) at Te = 623 K, Al + Q.C. + Al11V at re = 673 K and 723 K. The structure of the P/M Al93Fe3Cr2Ti2 alloy is Al + Q.C + Al23Ti9 at re = 673 K. The ultimate tensile strength (sigma (UTS)), 0.2% proof stress (sigma (0.2)), plastic elongation (S-p), Young's moduli (E), Vickers hardness (H-v) and specific strength (sigma (UTS)/rho) of the P/M Al93Fe3Cr2Ti2 alloy at room temperature are 660 MPa, 550 MPa, 4.4%, 85 GPa, 192 and 2.20 x 10(5) N m.kg(-1) respectively After heating for 300 s at 573 K, the sigma (UTS), sigma (0.2) and epsilon (P) are 360 MPa, 330 MPa and 1.5%, respectively. The Q.C. structure in the P/M Al93Fe3Cr2Ti2 alloy remains almost unchanged even after annealing for 720 ks st 573 K and the goad wear resistance against S50C steel is also maintained for the extruded alloy tested at the sliding velocity of 0.5 to 2 m/s.