Al-4%Cu単結晶および双結晶の応力腐食割れ
1973 年 37 巻 8 号 p. 917-922
詳細
1973 年 37 巻 8 号 p. 917-922
The stress corrosion cracking of single and bicrystals of Al-4% Cu alloys, prepared by the Bridgman method, was examined in regard to the relationships among precipitation, specimen axis and misorientation of grain boundary. The results obtained are as follows:
(1) Stress corrosion cracking always occurs along (100) traces in single crystals regardless of the different heat treatments.
(2) Fracture easily occurs in the specimens with a small angle between the specimen axis and the [100] direction, because they have high normal and shear stresses to the (100) plane.
(3) The fracture time of the bicrystals is long at tilt angles of less than 10° when the twist angle and the normal and shear stresses to grain boundary are constant. On the contrary, the fracture time is almost independent of the tilt angles which are larger than 10°.
(4) The fracture time of the bicrystals is shorter in the order of the specimens quenched or aged at 220°C, non-heat treated and aged at 130°C regardless of the misorientation.
(5) When the tilt and twist angles are within 10° and the angle between the specimen axis and the [100] direction is small, transgranular cracking is recoganized along (100) traces.
