SHAPE MEMORY ALLOY WIRE HAVING PLURAL TRANSFORMATION POINTS AND SHAPE MEMORY ALLOY SPRING BY USE OF SAME AND THEIR PRODUCTION

摘要

PURPOSE:To manufacture a shape memory alloy wire having plural transformation point, by subjecting a piece of seamless shape memory alloy wire with the same composition to heat treatment at partly different temps. CONSTITUTION:A piece of seamless wire 1 or coil spring material 5 of shape memory alloy with the same composition composed principally of TiNi of =50.3atom.% Ni concentration is partly covered with heat insulating materials 6, such as asbestos, etc., dissimilar in dimension, respectively, and then placed into furnaces of the same temperature to undergo heat treatment under the prescribed conditions. As a result, the wire 1 or spring material 5 of shape memory alloy having plural transformation temps. partly different owing to the difference in dimensions, such as thickness, etc., of the heat insulating material 6 can be obtained.