極低温における5083合金の機械的性質の温度依存性
1987 年 37 巻 4 号 p. 291-299
詳細
1987 年 37 巻 4 号 p. 291-299
Tensile tests were carried out in the temperature range from 4.2 to 293 K for 5083-O aluminum alloy. Temperature dependences of strength, ductility, toughness, work-hardenability, serrated deformation and cracking within intermetallic particles have been investigated in details especially from 4.2 to 70 K.
Increasing trends of the uniform elongation, the true stress corresponding to the ultimate tensile strength, toughness and the work-hardening exponent with decreasing temperature were changed drastically to decreasing trends below about 20 K. These changes in temperature dependences of the mechanical properties are due to the discontinuous slip of dislocations corresponding to large serrated flows on the load-displacement curves which appear in the temperature range from about 20 to 4.2 K. A large serrated flow was accompanied by a local heat generation. The discontinuous slip of dislocations corresponding to large serrated flow caused decrease in the work-hardening exponent and accelerated cracking within the large intermetallic particles.
