TC4钛合金脊柱螺钉失效分析

TC4钛合金脊柱螺钉在植入人体后,在低于其预期寿命时,发生断裂失效。为了避免该材料在今后使用过程中发生异常断裂事故,有必要分析这一断裂失效的原因,为改进材料的制备工艺提供必要的信息。为此本研究对这一生物材料断口作了扫描电镜观察及能谱分析,同时还作了化学成分分析与金相分析。结果发现断口处没有发生明显的塑性变形,且疲劳源、慢速和快速裂纹扩展区轮廓非常明显。认为该零件所用材料的冶金质量不是其失效原因,而疲劳断裂才是其真正的失效机制。

Failure Analysis for Titanium Alloy Backbone Screw

TC4 titanium alloy backbone screw has suddenly cracked after being implanted in human body and under its expected life. In order to avoid this abnormal failure, it is necessary to analyze the reasons for the failure. The fracture was observed by SEM, EDS analysis of scanning to this bio-material section. At the same time, composition and metallography of the sample were also analyzed. It is shown that there are no obvious plastic deformation on the section, and fatigue origins, slowly and fast developed fatigue stripe are obviously shown on the crack section surface. It is believed that metallurgical quality is not the reason for its failure, while fatigue is the real failure mechanism.