著者

菊池 将一 渡會 恵美 小山 毅士 栗田 大樹

出版者

公益社団法人 日本材料学会

雑誌

材料 (ISSN:05145163)

巻号頁・発行日

vol.71, no.12, pp.953-960, 2022-12-15 (Released:2022-12-20)

参考文献数

31

被引用文献数

1

---

Periodic TiB-reinforced titanium, which is defined as Ti-matrix surrounded by a network of TiB structures, was developed via powder metallurgy using TiB powders. The TiB composite was obtained by combining the CP titanium with 59 vol% TiB2 powders, and then mechanical milling was performed using a planetary ball mill to fabricate TiB powders. In this study, in order to investigate the near-threshold fatigue crack propagation in a periodic TiB-reinforced commercially pure titanium, stress intensity factor, K, decreasing tests were conducted under the force ratios from 0.1 to 0.8 in air at room temperature. After testing, crack profiles were observed by scanning electron microscopy to discuss the mechanism of fatigue crack propagation. In the periodic TiB-reinformed titanium, fatigue cracks were found to propagate preferentially through the network of TiB, which results in higher crack growth rate, da/dN. In contrast, the effect of microstructure on the threshold stress intensity range, ΔKth, in the TiB-reinforced titanium fabricated by TiB powders was disappeared by eliminating the crack closure phenomenon.