Department of Oral and Maxillofacial Radiology, Tokyo Dental College, Tokyo, Japan.
Graduate School of Keio University, Yokohama, Japan.
J Prosthodont Res. 2023 Oct 13;67(4):626-632. doi: 10.2186/jpr.JPR_D_22_00207. Epub 2023 Apr 8.
In this study, the fatigue properties of additively manufactured titanium clasps were compared with those of commercially pure titanium (CPTi) and Ti-6Al-4V (Ti64), manufactured using laser powder-bed fusion.
Fourteen specimens of each material were tested under the cyclic condition at 1 Hz with applied maximum strokes ranging from 0.2 to 0.5 mm, using a small stroke fatigue testing machine. A numerical approach using finite element analysis (FEA) was also developed to predict the fatigue life of the clasps.
The results showed that although no significant differences were observed between the two materials when a stroke larger than 0.35 mm was applied, CPTi had a better fatigue life under a stroke smaller than 0.33 mm. The distributions of the maximum principal stress in the FEA and the fractured position in the experiment were in good agreement.
Using a design of the clasp of the present study, the advantage of the CPTi clasp in its fatigue life under a stroke smaller than 0.33 mm was revealed experimentally. Furthermore, the numerical approach using FEA employing calibrated parameters for the Smith-Watson-Topper method are presented. Under the limitations of the aforementioned clasp design, the establishment of a numerical method enabled us to predict the fatigue life and ensure the quality of the design phase before manufacturing.
本研究比较了增材制造钛卡环与商用纯钛（CPTi）和 Ti-6Al-4V（Ti64）的疲劳性能，这些材料均采用激光粉末床熔合制造。
使用小冲程疲劳试验机，在 1Hz 下以 0.2 至 0.5mm 的施加最大冲程对每种材料的 14 个试件进行循环测试。还开发了一种使用有限元分析（FEA）的数值方法来预测卡环的疲劳寿命。
结果表明，当施加的冲程大于 0.35mm 时，两种材料之间没有观察到显著差异，但在冲程小于 0.33mm 时，CPTi 的疲劳寿命更好。FEA 中的最大主应力分布和实验中的断裂位置非常吻合。
通过使用本研究中卡环的设计，从实验上揭示了在冲程小于 0.33mm 时 CPTi 卡环在疲劳寿命方面的优势。此外，还提出了使用经过校准的 Smith-Watson-Topper 方法参数的 FEA 数值方法。在上述卡环设计的限制下，建立了一种数值方法，使我们能够在制造前预测疲劳寿命并确保设计阶段的质量。
