Structural and microhardness studies of Al-Ni-Cr alloy ingots

الملخص EN

Ingots of Al and Al-Ni-Cr (contains 0.25, 0.5, 0.99, 1.98 at.

% Ni-Cr) alloys were prepared by melting together wire aluminium, powder nickel and very small pieces of chromium in an electric furnace at 800 oC under an argon atmosphere.

XRD analysis after exposed the alloys to annealing at 560 oC for 1300 hr showed the emergence and growth of three binary phases: Al3Ni (Orthorhombic, a = 6.598Ǻ, b = 7.352 Ǻ, c = 4.802 Ǻ), Cr9Al17(Rhombohedral, a = 12.910, c = 15.677 Ǻ), and Ni2Cr3(Tetragonal, a = 8.82 Ǻ, c = 4.58 Ǻ) in addition to unknown phases.

The crystallite size decrease with increasing Ni-Cr contents exception the ratio 1.98 at.

%.

The results refer to rising of microhardness three times when raised the alloy density 0.1 g / cm3.