周期ミクロ強度勾配制御による多機能材料設計

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, Kth, in the TiB-reinforced titanium fabricated by TiB powders was disappeared by eliminating the crack closure phenomenon.

show abstract

Fabrication of High-Entropy Alloy CrMnFeCoNi with Bimodal Structure and Its Fatigue Crack Propagation Properties

Ito

Fujita

Kawaguchi

et al. 2022

J. Soc. Mat. Sci., Japan

View full text Add to dashboard Cite

High entropy alloys (HEAs), which have five or more principal elements with an equiatomic composition, exhibit multiple excellent mechanical properties. Superior fatigue properties would be required to use HEAs as structural components in engineering fields. The purpose of this study is to develop HEAs having high crack propagation resistance via melamine reduction-nitridation and powder metallurgy. The HEA with a bimodal structure was fabricated by sintering nitrided HEA powders. Stress intensity factor, K, decreasing tests were conducted under the force ratios, R, from 0.1 and 0.5 in air at room temperature to investigate the near-threshold fatigue crack propagation in CrMnFeCoNi alloys with a bimodal structure. Threshold stress intensity range, ΔKth, of nitrided HEAs compact tested at R = 0.1 was lower than that of the un-nitrided one, whereas ΔKth of nitrided HEAs compact tested at R = 0.5 showed almost the same as the unnitrided one and effective threshold stress intensity range, ΔKeff,th, was higher than that of the un-nitrided one. After testing, crack profiles were observed by scanning electron microscopy, and microstructures around crack profiles were analyzed using electron backscatter diffraction and electron prove micro analysis to discuss the mechanism of fatigue crack propagation. In some areas, fatigue crack paths in nitrided HEAs compacts were influenced by a bimodal structure.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

周期ミクロ強度勾配制御による多機能材料設計

Cited by 3 publications

References 37 publications

Effect of grain size on fatigue limit in CrMnFeCoNi high-entropy alloy fabricated by spark plasma sintering under four-point bending

Effect of grain size on fatigue limit in CrMnFeCoNi high-entropy alloy fabricated by spark plasma sintering under four-point bending

Development of Periodic TiB-Reinforced Titanium via Powder Metallurgy and Its Near-Threshold Fatigue Crack Propagation

Fabrication of High-Entropy Alloy CrMnFeCoNi with Bimodal Structure and Its Fatigue Crack Propagation Properties

Contact Info

Product

Resources

About