Effect of Third Elements on Pseudoelasticity in Fe₃Ga Alloys

Abstract:

Pseudoelasticity of Fe₃Ga polycrystals doped with third elements (Ti, V, Cr, Mn, Co, Ni, Si, Ge) was examined. Fe₃Ga polycrystals with the appropriate heat treatment were found to exhibit large pseudoelasticity based on reversible motion of dislocation dragging an antiphase boundary (APB). In Fe₃Ga crystals with the D0₃ superlattice structure, paired 1/4<111> superpartial dislocations mainly moved dragging the next-nearest-neighbor APB during loading. During unloading, the APB pulled back the superpartial dislocations resulting in the pseudoelasticity. The D0₃ ordered phase also developed in Fe₃Ga polycrystals with 2at% of the third elements. However, the strain recovery of Fe₃Ga polycrystals depended strongly on third element. Fe₃Ga polycrystals doped with 2at% of Mn, Cr and Co demonstrated large pseudoelasticity. In contrast, the other doped elements decreased the amount of strain recovery. The frictional stress of 1/4<111> superpartial dislocations and the back stress due to the APB, acting on the dislocations, changed by doping the third elements, which was closely related to the pseudoelastic behavior. It is also noted that there was a good correlation between the APB back stress and the ordering temperature from the B2 to D0₃ phase.

• Periodical: Materials Science Forum (Volumes 706-709)
• Pages: 2032-2037
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.706-709.2032
• Online since: January 2012
• Authors: Hiroyuki Y. Yasuda, Tsuyoshi Furuta, Takenori Maruyama
• Keywords: Antiphase Boundary (APB), Dislocation, Pseudoelasticity

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