329 アルミ合金鋳物の人工時効が熱疲労特性に与える影響について(OS1-5 環境・高温および熱疲労)(OS1 高強度材・表面改質材の疲労と破壊)  [in Japanese] 329 Effect of Thermal Fafigue Phenomena of Aluminum Alloy by Artificial Aging  [in Japanese]

In the past efforts were focused on pursuing the formulation of chemical composition rather than the heat treatment conditions of aluminum alloys which become strong as being aged. Studies on optimizing the heat treatment conditions are few, and reports dealing with heat treatment conditions and test conditions based on actual use are quite rare. In this study, two aluminum alloys, AC4C and AC2B, as representative alloys being used for vehicle engines, were T6 tempered and additional annealed before measuring the mechanical properties and thermal fatigue of the materials. Especially temperature dependency was evaluated to compare the two materials. Thermal fatigue life was evaluated only on AC4C, and the effects of aging on fatigue life were clarified by studying relation between plastic strain energy density and fatigue life, as well as by observing the microstructure of aged samples by TEM.