Mechanisms of Plastic Deformation in Microcrystalline and Nanocrystalline TiNi-Based Alloys

作者：Surikova N S^*; Klopotov A A; Korznikova E A

来源：Physics of Metals and Metallography, 2010, 110(3): 269-278.

DOI：10.1134/S0031918X10090103

• plastic deformation
• twinning
• martensitic transformation
• fragmentation
• texture
• nanostructure
• microstructure
• amorphous state

Mechanisms of plastic deformation of a high-temperature B2 phase that act upon tension, compression, and high-pressure torsion in TiNi-based single crystals have been studied depending on the crystal orientation. For the crystals with orientations located near the [(1) over bar 11] and [(1) over bar 12] poles in the standard stereographic triangle, multiple dislocation slip prevails upon both compression and tension. In "hard" crystals with the deformation axis close to the [001] direction, in which the Schmid factors for dislocation slip are close to zero, the main deformation mechanisms are the mechanical twinning in the B2 phase and the stress-assisted B2 -> B19' martensitic transformation. All the above listed mechanisms take part in the formation of the {111}< hkl > texture. The mechanism of the change in the orientation of "hard" polycrystalline grains upon the formation of a nanocrystalline and amorphous-crystalline state has been demonstrated on the example of the evolution of the structure of [001] crystals upon severe plastic deformation in a Bridgman cell.

• 出版日期2010-9