Different fragments of a hot-rolled and homogenized Cu–Zn–Al shape memory alloy (SMA) were subjected to thermal cycling by means of a differential scanning calorimetric (DSC) device. During thermal cycling, heating was performed at the same constant rate of increasing temperature while cooling was carried out at different rates of decreasing temperature. For each cooling rate, the temperature decreased in the same thermal interval. During each

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

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

The paper reports the effects of 100 to 500 training cycles applied to lamellar specimens of a Cu-Zn-Al Shape Memory Alloy (SMA). The training procedure consisted in the bending, during the cooling to room temperature (RT) of martensitic specimens, by the load fastened at their free end and in load lifting by Shape Memory Effect (SME) during heating up to austenitic domain. During cooling, the concave surface of bent specimens was compressed and

Fe-14 Mn-6 Si-9 Cr-5 Ni (mass. %) shape memory alloys (SMAs) were produced from raw powders employed both in initial commercial state and in a mixture state of equal fractions of commercial and mechanically alloyed (MA’d) particles. After blending, pressing and sintering, powder compacts were hot rolled (HR’d) and solution treated (ST’d) before being machined into plane-parallel lamellas. Specimens with special geometry were pre-strained on