Al-Li合金の疲労における切欠き感度
1994 年 43 巻 490 号 p. 840-846
詳細
1994 年 43 巻 490 号 p. 840-846
In order to evaluate the notch fatigue strength and notch sensitivity of aluminum-lithium alloys, 2090 and 8090, rotating bending fatigue tests have been carried out using circumferential notched specimens with different stress concentration factors. The results obtained were compared with those of conventional aluminum alloys, 2024-T4 and 7075-T6511. It was found that aluminum-lithium alloys showed superior notch fatigue strength to conventional aluminum alloys. The notch sensitivities for crack initiation limit of aluminum-lithium alloys were lower than those of 7075-T6511, while they were nearly equal to those of 2024-T4 for blunt notches, but tended to become lower with further increase of the sharpness of notch. The notch sensitivities for crack propagation limit were also lower in aluminum-lithium alloys, in particular 8090 alloy, than in conventional aluminum alloys. It was suggested that the decreased notch sensitivities of aluminum-lithium alloys were attributed to crack propagation mode and high propagation resistance related to their microstructures.
