Highlights•Local crystalline structure of TiNiCu SMA is investigated using EXAFS.•Peculiarities of Ni and Cu local environment are found.•Ti atoms show greater mobility relative to Ni atoms.•Ni local environment change is significant for shape memory effect.
AbstractThe work deals with the research of the effect of pulsed laser radiation (λ=248 nm) on the structure and the manifestation of the shape memory effects (SMEs) in the Ti50Ni25Cu25 alloy, produced by melt spinning technique. It has been revealed that the proposed method of laser treatment leads to the formation of structural amorphous-crystalline composite demonstrating the pronounced two-way SME. A dependence of the two-way SME on the number of laser radiation pulses was determined.
AbstractThe paper presents the development of microtweezers on the basis of a shape memory TiNiCu alloy produced by melt-spinning technique in the form of amorphous-crystalline ribbon at around 40 μm of thickness. The ribbon is capable of executing reversible bending deformations in a heating/cooling cycle. Two elements of 400 μm wide were prepared from the ribbon and joined in such a way that in the initial state at ambient temperature a gap in the range from 10 μm to 100 μm was set between them. On heating above the austenite transformation finish temperature of the alloy, the elements (the tips of the microtweezers) are moving in a fully closed position and on cooling down they are returning to the initial open position. The microtweezers are managed through the temperature control device using the Peltier element.It is shown that the response speed of the gripping essentially depends on the heating temperature as well as on the temperature of preheating. At the optimum control mode the response time of the grippers was about 1 second. Developed micromechanical device can be used for gripping and handling of micro-objects smaller than 100 μm, in particular, in microelectronics, robotics or microbiology.