Effect of heat treatment on redial force of NiTi tube stent

One of the main factors in tube stents is controlling RF in a range of acceptable Af. In this study we would like to perform series of experiment to evaluate the effect of heat setting parameters on RF in nitinol tube stent. For this purpose we perform heat treatment on cold work NiTi stent with 55% Ni in a range of 400 to 560 for different time. Af measurement test also perform by the bend and free recovery method to investigate Af affected by heat treatment. Radial force test was performed on all stents to maximum 50 % reduction of OD. Loading, unloading and maximum of RF were investigated in different heat treatment condition. In this research the correlation of RF stability with mass and time interval between heat setting and redial force test also investigated.