Metallurgical Characterization of M-Wire Nickel-Titanium Shape Memory Alloy Used for Endodontic Rotary Instruments during Low-cycle Fatigue
Metallurgical Characterization of M-Wire Nickel-Titanium Shape Memory Alloy Used for Endodontic Rotary Instruments during Low-cycle Fatigue
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DOI：
10.1016/j.joen.2011.09.028
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发表时间：
2012-01-01
影响因子：
4.2
通讯作者：
Gao, Yong
中科院分区：
文献类型：
--
作者：
Ye, Jia;Gao, Yong
简介：与传统超弹性NiTi丝相比，由新型镍钛合金（M-Wire）制成的旋转器械具有更好的抗循环疲劳性和机械性能。本研究旨在表征受控应变幅下M-导丝在整个循环疲劳过程中的微观结构变化。研究方法：根据在室温和300 rpm转速下进行应变控制（类似于4%）旋转弯曲疲劳试验的30件M-导丝样品计算平均疲劳寿命。通过不同的冶金表征技术，包括差示扫描量热法、维氏显微硬度和透射电子显微镜，在4个不同阶段（接收状态、平均疲劳寿命的30%、60%和90%）研究了M线的显微组织演变。结果如下：在旋转弯曲疲劳试验期间，未发现收到的M-导丝和疲劳样品之间的奥氏体完成温度存在统计学显著差异（P > 0.05）。但差异有显著性（P
Introduction: Rotary instruments made of a new nickel-titanium (NiTi) alloy (M-Wire) have shown improved cyclic fatigue resistance and mechanical properties compared with those made of conventional superelastic NiTi wires. The objective of this study was to characterize microstructural changes of M-Wire throughout the cyclic fatigue process under controlled strain amplitude. Methods: The average fatigue life was calculated from 30 M-Wire samples that were subjected to a strain-controlled (similar to 4%) rotating bend fatigue test at room temperature and rotational speed of 300 rpm. Microstructural evolution of M-Wire has been investigated by different metallurgical characterization techniques, including differential scanning calorimetry, Vickers microhardness, and transmission electron microscopy at 4 different stages (as-received state, 30%, 60%, and 90% of average fatigue life). Results: During rotating bend fatigue test, no statistically significant difference (P >.05) was found on austenite finish temperatures between as-received M-Wire and fatigued samples. However, significant differences (P