镍钛产品疲劳测试早期断裂原因分析

Cause Analysis of Early Fracture of Nitinol Device during Fatigue Test

镍钛合金医疗器械产品,在疲劳测试过程中发生早期断裂,但该批原材料经检验是合格的。通过金相显微镜、扫描电镜及能谱等对产品断裂原因进行分析。结果表明,产品早期断裂是由于在承受最大应力的区域,局部存在夹杂物缺陷,致使产品在周期性疲劳应力作用下,产生早期疲劳断裂失效。

Early fracture of nitinol medical device occurred during the fatigue testing,but the raw material is qualified. The fracture of device was analyzed by means of metallographic microscope,SEM and EDS etc. The results show that the early fracture of the device is due to the local existence of the impurity defects in the areas subject to the maximum stress,resulting in fatigue failure of the device under cyclic fatigue stress.