Production of nanograined intermetallics using high-pressure torsion

Materials Research

Ali Alhamidi¹  Kaveh Edalati¹  Zenji Horita¹ 

[1] ,Kyushu University Faculty of Engineering Department of Materials Science and EngineeringFukuoka,Japan

关键词: severe plastic deformation (SPD);    ordering;    phase transformation;    micropillar;    AlNi;    TiAl;    aluminide;   

DOI  :  10.1590/S1516-14392013005000057

来源: SciELO

【 摘 要 】

Formation of intermetallics is generally feasible at high temperatures when the lattice diffusion is fast enough to form the ordered phases. This study shows that nanograined intermetallics are formed at a low temperature as 573 K in Al- 25 mol% Ni, Al- 50 mol.% Ni and Al- 50 mol% Ti powder mixtures through powder consolidation using high-pressure torsion (HPT). For the three compositions, the hardness gradually increases with straining but saturates to the levels as high as 550-920 Hv. In addition to the high hardness, the TiAl material exhibits high yield strength as ~3 GPa with good ductility as ~23%, when they are examined by micropillar compression tests. X-ray diffraction analysis and high-resolution transmission electron microscopy reveal that the significant increase in hardness and strength is due to the formation of nanograined intermetallics such as Al3Ni, Al3Ni2, TiAl3, TiAl2 and TiAl with average grain sizes of 20-40 nm.

【 授权许可】

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