The present work reports the influence of the loading mode provided during training under constant stress, in bending, applied to lamellar specimens of Cu-Zn-Al shape memory alloys (SMAs). During training, the specimens were bent by a load fastened at their free end, while being martensitic at room temperature and they lifted the load by one-way effect (1WE), during heating up to austenitic field. On cooling to martensite field, the lower concave

This paper introduces an adapted high-speed high pressure torsion (HS-HPT) method of severe plastic deformation applied for obtaining shape memory alloy (SMA) active elements with revolution symmetry, able to develop axial displacement/force. Billets with circular crown forms were cut from Fe-28Mn-6Si-5Cr (mass%) SMA ingots and, by means of HS-HPT technology, were directly turned into modules, with truncated cone shell configurations. This process

In this work, the aim was to investigate how the deformation by cold rolling affects the microstructure and transformation temperatures of Fe-14Mn-6Si-9Cr-5Ni alloy prepared by powder metallurgy route. The characteristic of the martensitic transformation in the given alloy composition was investigated in terms of the amount of deformation via cold rolling. Mechanical alloying was applied for reaching better chemical homogenization level in powder

The present paper aims to identify a sequence of bulk-deformation processes able to produce sufficient quantities of ultra fine grained (UFG) volume as to be of interest for practical purposes. Samples of aluminum Al 1100alloy (98.41 % Al) were subjected to repetitive equal channel angular pressing (ECAP) at room temperature, up to in eight passes. Severely plastic deformed (SPD) specimens were cold rolled in thin strips which were subjected to structural

Lamellar specimens of Cu-Zn-Al Shape Memory Alloy (SMA) were trained in bending under as much as 500 cycles, until two-way shape memory effect (2WE) was obtained. Trained specimens were further tested by means of a hydraulic installation where, heating-cooling cycles were performed in oil conditions. Considering that the lower concave surface of the specimens was kept in compressed state while the upper convex surface was kept in elongated state,

Samples of Fe-14Mn-6Si-9Cr-5Ni (mass. %) shape memory alloy were sintered from two powder mixtures: (i) as blended (0_MA) and (ii) equal amounts of as blended and mechanically alloyed (MA’d) powders (50_MA). In order to increase the compactness degree, different specimens were hot rolled at 1373 K and the last rolling pass was performed at four different temperatures: (i) room temperature (RT); (ii) 873 K; (iii) 1073 K and (iv) 1373 K. In order

The paper reports the evolution of surface relief and shape memory behavior in an Fe–28Mn– 6Si–5Cr (mass%) shape memory alloy (SMA) as a function of the applied hot working procedure. The objective of this paper is to discuss the relationship between surface relief characteristic, structural changes and the type of hot working processing. Particular aspects concerning the relief of martensite plates were reported after the alloy was subjected

Processing effects caused by homogenization heat treatment, hot rolling and solution treatment in three Fe-Cr-Ni-C alloys, with different Ni amounts, were analysed by optical and scanning electron microscopy. X-Ray diffraction (XRD), magnetic hysteresis data, Vickers micro-hardness and micro-indentation measurements were used in order to reveal chemical composition and processing effects. Dendrite fragmentation, caused by hot rolling and thermoelastic

Two different types of Fe-base shape memory alloys (SMAs), obtained by different processing methods, were comparatively analyzed from the point of view of: (i) structural characterization, (ii) morphologic aspects and (iii) mechanical behaviour. For this purpose, heat treated specimens of Fe-9Cr-4Ni-0.33C and in Fe-28Ni-17Co-11.5 Al-2.5 Ta (mass. %) were produced and prepared for X-ray diffraction (XRD) and scanning electron microscopy (SEM) observations,

An Fe-14Mn-6Si-9Cr-5Ni (mass. %) shape memory alloy obtained through powder metallurgy, containing a mixture of 50% commercial powders and 50% mechanical alloyed powders, was subjected to different heat treatments in order to increase chemical homogeneity degree. The heat treatments consisted of using three types of treatment atmospheres (air, nitrogen and argon) and three isothermal maintaining times (6 × 102 s, 24 × 102 s and 48 × 102 s). The