Mechanical Properties of Fe–Mn–Si Based SMA and the Application

Abstract

The SME (shape memory effect) in an Fe-Mn-Si based SMA is governed by motion of Shockley partial dislocations which carry the fcc $ hcp phase transformations. The degree of SME is determined by preservation of the partial dislocations whereas the strength is determined by the internal stress opposing against the dislocation motion. The increase in the internal stress tends to induce dislocation reactions which ruin the preservation of the Shockley partials and hence to decrease the degree of SME. Nevertheless, usage of this SMA for construction of a large structural product has recently gained much attention even with sacrifice in the degree of SME. Upon application of this SMA in such a field, the optimum condition has to be searched both in the mechanical properties of the SMA itself and the type of the usage in the sense of deformation mode such as elongation, contraction, bending, twisting and so on. In this paper, the dislocation motion responsible for a good SME with high strength will be discussed on the ground of the basic knowledge of the dislocation generation, the motion and the reactions.

Phase transformation during mechano-synthesis of nanocrystalline/amorphous Fe–32Mn–6Si alloys

“…Fe-Mn-Si alloys are a class of smart materials due to their suitable shape memory effect (SME), excellent machinability and formability, low cost, good weldability and corrosion resistance, and high strength having several industrial applications such as dampers, pipe couplings, big shape memory devices, hard metals or alloys joining, oxygen blowing nozzles and so on [1][2][3][4][5][6][7][8][9][10][11]. The production of stress induced martensite (ε, hcp) from parent austenite phase (γ, fcc) and the reverse transformation (γ to ε) during the heating cycle are the origins of SME in this alloying system [12][13][14][15][16][17][18].…”

Effect of Sintering Time on the Densification, Microstructure, Weight Loss and Tensile Properties of a Powder Metallurgical Fe-Mn-Si Alloy

“…In the family of metallic shape memory alloys (SMAs), Fe-Mn-Si SMAs exhibit relatively low costs of both raw materials and processing in comparison with their Ni-Ti alloys and Cu-based counterparts [4,5]. This makes Fe-Mn-Si shape memory alloys a promising candidate for various civil engineering applications such as pipe joints and rail coupling [6][7][8][9][10]. Recently, temporary biomedical devices such as cardiovascular stents and bone fixation plates have been discussed as potential applications of Fe-Mn-Si alloys due to their reasonable biodegradability, good biocompatibility and mechanical properties [11][12][13][14][15].…”

Effect of Sintering Time on the Densification, Microstructure, Weight Loss and Tensile Properties of a Powder Metallurgical Fe-Mn-Si Alloy

“…In the family of metallic shape memory alloys (SMAs), Fe-Mn-Si SMAs exhibit relatively low costs of both raw materials and processing in comparison with their Ni-Ti alloys and Cu-based counterparts [4,5]. This makes Fe-Mn-Si shape memory alloys promising candidates for various civil engineering applications such as pipe joints and rail couplings [6][7][8][9][10]. Recently, temporary biomedical devices such as cardiovascular stents and bone fixation plates have been discussed as potential applications of Fe-Mn-Si alloys due to their reasonable biodegradability, good biocompatibility, and mechanical properties [11][12][13][14][15].…”