Rapidly solidified bulk shape memory alloys

Rapidly solidified Ni-Ti bulk shape memory alloys have been manufactured using the suction method. The as-solidified rods have been characterized using DSC and internal friction methods. In the as solidified state it is shown that an inhomogenous structure may occur due to the change in the cooling rate from the outer surfaces in contact with the cooled mold and the core. Two transitions are clearly observed on cooling the as-quenched sample while during heating only one distinct peak appears on both DSC and internal friction. The heat treatment applied to the rapid solidified specimen lead to a volume transformation, similar to the one observed in similar samples prepared via the classical path. The analysis of the relaxation peak is consistent with similar known results.