The invention provides a functional
alloy capable of obtaining permanent
magnet performance (stretching induced
magnetic effect) through stretching and a preparation method of the functional
alloy. The expression of the functional
alloy is FeaNibCocAld, a, b, c and d respectively represent the atomic percentage (at.%) of corresponding elements, a = 40-50, b = 25-35, c = 10-20, d = 5-15, and a + b + c + d = 100. The preparation method of the functional alloy comprises the steps of
smelting, rolling and heat treatment. The BCC magnetic particles are precipitated and separated out through rolling and heat treatment processes, so that the BCC magnetic particles have the special performance of generating magnetic force under the action of
tensile strain. And the number of BCC magnetic particle precipitates can be controlled by adjusting the heat treatment temperature, so that the
magnetic field intensity of the alloy after breaking is regulated and controlled. The maximum magnetic induction intensity of the functional alloy after
tensile fracture is increased to 122 Gs from 2Gs of an original alloy through rolling and heat treatment processes, and the maximum magnetic induction intensity of the functional alloy after
tensile fracture can be regulated and controlled within a certain range by adjusting the heat treatment temperature. The effect of obtaining the permanent
magnet performance through stretching is found for the first time, a method for regulating and controlling the magnetic induction intensity is found, stress changes and
magnetic signal changes can correspond to each other through the phenomenon, and therefore the method is expected to be applied to some specific equipment.