Nanostructure Al—Fe—Cr alloys reinforced by quasicrystalline particles for high temperatures application

Abstract

The features of structure and mechanical properties of nanostructured Al—Fe—Cr alloys with Ti and Zr alloying strengthened by quasicrystall particles were studied. Semi-finished products from these alloys were obtained without sintering by compacting powders produced by atomization of the melt by water under high pressure and subsequent extrusion of compacts in pre-evacuated and hermetic capsules. Methods of investigation: transmission electron microscopy including high-resolution, X-ray structural analysis, mechanical tensile testing measurement of micro- and macrohardness. Investigations were carried out at 20⁰С and after prolonged annealing at 300⁰ С. It was shown that Al matrix with grains ≤500 nm reinforced by quasicrystalline particles with size from 40 to 200 nm are formed in the rods of alloys on Al—Fe—Cr base obtained from wateratomized powders by developed technology. Chemicall compozition of Quasicrystalline particles were determined. It is proved that plasticity of semi-finished alloys Al—Fe—Cr are practically independent from annealing time and have the level of 7,0—8,4%. Strength and hardness are some reduced. Thus, for Al₉₄Fe_2.5Cr_2.5Ti₁ alloy at T_test = 300⁰С , UTS = 345 MРa; after aging at 1000 hours — 296 MPa, hardness decreases from 1980 MPa to 1930 MPa, respectively. Thus, the developed alloys exceed the requirements of modern aviation industry. Full text download