Abstract
In order to develop a brain spatula or a brain retractor made of a shape memory alloy (SMA), the bending deformation characteristics of the brain spatula of TiNi SMA made by the precision casting were discussed. The results obtained can be summarized as follows. (1) The maximum force obtained from the cyclic three-point bending test increases from first cycle to tenth cycle and a rate of increase is low after tenth cycle. (2) In the cyclic three-point pulsating-plane bending, recovery strain and maximum force change slightly except for initial cycle. Residual strain disappears after heating. (3) The fatigue life in pulsating-plane bending both with heating and cooling and at room temperature is longer than that in alternating-plane bending. (4) If bending direction of brain spatula is decided as pulsating, the change of bending deformation property is small during cyclic use, and long-life is achieved.
