Journal Published Online: 10 March 2023
Volume 12, Issue 2

Gigacycle Fatigue Properties of Wrought Aluminum Alloys

CODEN: MPCACD

Abstract

Fatigue data sheets of the National Institute for Materials Science disclose the results of gigacycle fatigue tests conducted on wrought aluminum alloys. The materials tested were hot-rolled plates and extruded round bars of A5083P-O (two heats), A7075-T6 (three heats), and A6061-T6 (three heats). The fatigue testing methods were rotating-bending at 100 Hz, ultrasonic at 20 kHz, and uniaxial at 100 Hz. The rotating-bending fatigue tests were conducted for 3 years to reach 1010 cycles. The ultrasonic and uniaxial fatigue tests were also conducted at high stress ratios. This study analyzed the fatigue life data, clarifying frequency effects, presence or absence of fatigue limits, and stress ratio effects. The three types of fatigue tests revealed equivalent results, meaning that frequency effects and stress gradient effects were negligible in the wrought aluminum alloys. Frequency effects were visible in several cast aluminum alloys owing to the influence of humidity, but the wrought aluminum alloys were observed to be insensitive to humidity. Many specimens were fractured at >107 cycles, whereas the degradation of fatigue strength after 107 cycles was very small in A5083P-O but large in A7075-T6 and A6061-T6. A5083P-O revealed fatigue limits at around 107 cycles. The heat treatment effects determined the presence or absence of fatigue limits because the equivalent tensile strengths between A6061-T6 and A5083P-O excluded the possibility of tensile strength effects. The stress ratio effects on gigacycle fatigue strengths of the wrought aluminum alloys are reasonable and can be estimated in conventional ways.

Author Information

Furuya, Yoshiyuki
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Nishikawa, Hideaki
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Hirukawa, Hisashi
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Nagashima, Nobuo
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Takeuchi, Etsuo
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Pages: 15
Price: $25.00
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Stock #: MPC20220082
ISSN: 2379-1365
DOI: 10.1520/MPC20220082