Dislocation motion on octahedral and cube planes in Fe₃Ge polycrystals

Abstract

An intermetallic compound of L1₂ ordered Fe₃Ge was examined by compression in bulk at various temperatures and by semi-in-situ compression of a thin foil at room temperature. This alloy is known to show monotonic decrease in yield strength being quite different from the other well-known L1₂ intermetallics. It is shown by stereomicroscopy, Burgers vector analyses and semi-in-situ experiments that ⟨112⟩ types of slips along the {111} faults may contribute to generate glide dislocations on {001} planes, which eventually act as multiplication sources for the cube slips to govern the essential part of the macroscopic deformation. The yield strength is confirmed to decrease monotonically up to 500 K and rapidly upon approaching the L1₂→D0₁₉ transformation temperature with a drastic increase in the strain rate sensitivity. The strengthening mechanism in this dual phase alloy of Fe₃Ge is discussed in terms of dislocation motion on both octahedral and cube planes by analysing the results of TEM observations with the information of Schmidt factors.

Notes

†Present address: Toyota motor corporation, Power train development group, Toyota-shi, Aichi 471-8571, Japan.

‡Present address: Honda R&D Co. LTD. Tochigi R&D Center, 4630 Shimotakanezawa, Haga-machi, Haga-gun, Tochigi 321-3393, Japan.

Additional information

Notes on contributors

M. Taniguchi†

†Present address: Toyota motor corporation, Power train development group, Toyota-shi, Aichi 471-8571, Japan.

K. Morizumi‡

‡Present address: Honda R&D Co. LTD. Tochigi R&D Center, 4630 Shimotakanezawa, Haga-machi, Haga-gun, Tochigi 321-3393, Japan.