This revision adds another transformation temperature term, A95, defined as the point where the specimen is 95% recovered. When there is retained cold-work in the specimen, the recovery curve can exhibit a region of reduced slope near the end of the recovery. When using the traditional tangent method on such a curve, the tangent is drawn to the steepest portion of the curve, resulting in an Af value that is far from the point of full recovery. Use of A95 instead of Af may be preferred in these cases.
Keywordsfree recovery; nickel titanium; nitinol; shape memory; transformation temperature;