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-F e-M-Ti (M = V, Cr, Mn) alloys with a diameter of 8 mm and a length of 300 m m 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 quas icrystal (Q.C.) at Te = 623 K, Al + Q.C. + Al11V at re = 673 K and 723 K. T he structure of the P/M Al93Fe3Cr2Ti2 alloy is Al + Q.C + Al23Ti9 at re = 6 73 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 a t 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. T he Q.C. structure in the P/M Al93Fe3Cr2Ti2 alloy remains almost unchanged e ven after annealing for 720 ks st 573 K and the goad wear resistance agains t S50C steel is also maintained for the extruded alloy tested at the slidin g velocity of 0.5 to 2 m/s.