ENHANCEMENT OF HIGH-TEMPERATURE MECHANICA L STRENGTH OF TINI FIBER ALCOMPOSITE INDUCED BY SHAPE-MEMORY EFFECT/

This paper describes the shape memory effects of TiNi fiber Al matrix (TiNi/Al) composites on enhancement of its mechanical properties: tens ile and fatigue resistance. A TiNi/Al composite was processed by a pow der metallurgical route. The yield stress and fatigue resistance showe d that they would increase with prestrain at temperature above the aus tenitic finish temperature of TiNi fiber (A(f)). The increases in tens ile properties (yield stress) and fatigue resistance were attributed t o the compressive stress field in the matrix which was induced when pr estrained TiNi fibers shrank to its initial length upon heating above A(f). The predictions based on the analytical model agreed reasonably well with the experiment.