Application Temperature Range of Temperature Memory Effect in Deformed TiNi Alloys

The application temperature range of temperature memory effect (TME) in deformed TiNi alloys was studied in this paper. The TME could be used in a wider temperature range when the specimen cold-rolled in a high deformation. And, the “highest” application temperature of TME could increase with the deformation, and finally rise to 573K with deformed 30%. This temperature no longer changes in higher deformations, while the characteristic of TME still increase with the deformation below 573K. This is due to the dislocation texture and deform-induced martensite structures restrain the reverse martensite transformation. And the restraint disappears when specimens are annealed more than 573K.

Structural-Mechanical Control of Bypass Reactivity in LISB for Space Application Using Alloys with Shape Memory Alloys

Keywords: Lithium-ion storage battery (LISB), bypass device, shape memory effect (SME) thermal treatment, reactivity, reliability Abstract. Deformation and strength characteristics of a thermal drive spring made of alloy with shape memory effect (SME) оn the base of TiNi in bypass device (BD) of Lithium-ion storage battery (LISB) for space application were investigated. A technique was developed for this spring thermal preparation for a certain magnitude of shape memory deformation, due to which during reverse martensite transformation a spring generates reactive force, sufficient for BD operation. It allowed to develop small-sized multiple action BDs for LISBs intended for “Glonass-K” spacecrafts. Study of technological and operational factors’ impact proved high level of BD failure-free operation.

Influence of Ultrasonic Treatment on Shape Memory Effects in Ti-50,4at.%Ni Alloy

In the present study we investigate the effect of ultrasonic treatment on the functional properties of Ti 50,4at.%Ni alloy after the processing in free and pre-deformed conditions. It is shown that the shape memory effect and its realization peculiarities depend on the parameters and conditions of ultrasonic influence. Ultrasonic treatment of preliminary deformed TiNi alloy in pre-deforming conditions promotes the reduction of strain restoring at the subsequent heating through the temperature interval of reverse martensite transformation. I. e. some setting of induced strain occurs during the ultrasonic treatment of material in pre-deforming conditions. In the specimens after ultrasonic treatment, it is observed the extension of shape recovery temperature range in the first thermal cycle, as well as the dependence of strain recovery temperature dynamics on the power of ultrasonic influence. Also it is established that ultrasonic treatment helps to increase the shape memory effect.

Effect of Annealing Temperature on the Transformation Temperature and Texture of Ni47Ti44Nb9 Cold-Rolled Plate

Transformation behaviors and texture of Ni47Ti44Nb9 cold-rolled plates were studied by differential scanning calorimetry and X-ray diffraction test. R phase transformation does not occur in Ni47Ti44Nb9cold-rolled plate annealed at 350°C-750°C followed by quenching into the water. Martensite transformation temperature first increases and then decreases with increment of annealing temperature, and the maximum achieves at 700°C. The heat of reverse martensite transformation increases, while hardness decreases as annealing temperature increases. The major texture of cold-rolled plate is {332} and spread from {332} to {110}. When the annealing temperature is above 600°C, the major textures are {332} and {111} recrystallization texture in secondary cold-rolled plate.