The invention discloses a preparing method of a memory
alloy nano lamination Ni / Ti preformed blank, and belongs to the technical field of functional composites. The method comprises the steps of firstly, material preparing, secondly, packaging and thirdly, rolling.
Room temperature accumulative roll bonding is adopted, in combination with wrapping of a jacket, the deforming is limited and obstructed, Ni / Ti coordinative deforming is facilitated, and the problems that in the traditional
smelting process,
NiTi alloy easily introduces
impurity elements, the material
machining property is poor, inthe cold
machining process, deforming resistance is large, and the pass deforming amount is small are solved. Due to the fact that three segments of
accumulative roll bonding are carried out at the
room temperature, the middle process is not annealed, the
residual stress of the finally-composited Ni / Ti layered preformed blank is large, the activity between Ni atom and Ti atom interfaces is high, the layered Ni / Ti preformed blank is high in
hardness, and the
elastic modulus is high. Time needed by generating of the NiTi
shape memory alloy through the certain-temperature reaction
diffusion of Niand Ti is shorter, TiNi
alloy grains can be generated through refining to a certain degree, the NiTi high-quality
shape memory alloy is improved, the grains are thin, the
phase change temperature stability can be improved, and the austenitization
phase change temperature is slightly increased.