Memoirs of the Faculty of Engineering, Okayama University 34巻 1-2号
2000-03-27 発行
榊原 精
Department of Mechanical Engineering
Tanimoto, Tadashi
Department of Mechanical Engineering, Okayama University of Science
Matsushima, Takahisa
Graduate School of Okayama University of Science (Present: Daiwabo Co., Ltd.)
Hosokawa, Norio
Department of Mechanical Engineering, Okayama University of Science
Kanadani, Teruto
Department of Mechanical Engineering, Okayama University of Science
Repeated tensile fatigue strength of the low temperature age-hardened Al-Zn alloys is investigated varying the specimen thickness. Fatigue strength of the age-hardened specimens decreases with the specimen thickness when the
specimen is thinner than a certain thickness, whereas fatigue strength of non age-hardened specimens, i.e., pure aluminum and dilute Al-Zn alloy, does not depend the specimen thickness. The dependence of fatigue strength on the thickness of age-hardened specimen is considered to be caused by the decrease of the strength of specimen as a whole, as a result of increase in volume ratio of the soft surface layer formed after age-hardening with decreasing specimen thickness.