Fatigue Strength of Ti-6Al-4V Alloys Containing Small Artificial Defects

被引：0

作者：

Matsunaga, Hisao ^{[1
]}

Murakami, Yukitaka ^{[1
]}

Kubota, Masanobu ^{[1
]}

Lee, Joon-Hyun ^{[2
]}

机构：

[1] Dept. of Mech. Engineering Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan

[2] School of Mechanical Engineering, Pusan National University, 30 Changjeon-Dong, Kumjeong-ku, Pusan 609-735, Korea, Republic of

来源：

| 2003年 / Society of Materials Science Japan卷 / 09期

关键词：

Compaction - Crack propagation - Defects - Forging - Interfaces (materials) - Microstructure - Strength of materials - Tensile stress;

D O I：

暂无

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学科分类号：

摘要：

The effects of small defects on the fatigue strength of Ti-6Al-4V were investigated in tension-compression fatigue tests. To simulate the defects, holes having 50, 200, 400, 760 and 1000μm diameters were introduced onto the surface of a series of specimens (Series A). Another series of specimens (Series B) were prepared to investigate the effect of a burr or a pre-crack which was introduced at the edge of the artificial hole. For Series A specimens, the fatigue limit was defined as the threshold for crack initiation from the edge of the hole. For Series B specimens, the fatigue limit was defined as the threshold for crack propagation from the burr or the tip of the pre-crack. The results of the fatigue tests for R=-1 indicated that the fatigue limits of Series B specimens were 20-60MPa lower than those of Series A specimens. In contrast to steels, non-propagating cracks did not form at the holes, a feet associated with the relatively high stress level for crack initiation from hole in Ti-6Al-4V It was also found that the √area parameter model underestimated the fatigue limit of Series A specimens, but the model accurately predicted the fatigue limit defined by crack-growth threshold for Series B specimens. In addition it was noted that the presence of a burr resulted in a decrease in fatigue life, since the burr facilitated the crack initiation process.

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