Creep characteristics of a diecast AM50 magnesium alloy

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 37; no. 1; pp. 243 - 248
• Main Authors: ISHIMATSU, Naoya, TERADA, Yoshihiro, SATO, Tatsuo, OHORI, Koichi
• Format: Journal Article
• Language: English
• Published: New York, NY Springer 2006; Springer Nature B.V
• Subjects: Alloys; Applied sciences; Creep; Creep tests; Exact sciences and technology; Magnesium; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals creep; Metals. Metallurgy; Temperature; Tensile strength; Creep; Mechanical properties
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-006-0169-9

Tensile creep tests were conducted to examine the creep behavior of a diecast AM50 magnesium alloy in the temperature range from 423 to 498 K. A normal transient creep stage is followed by a minimum creep rate stage and finally by an accelerating stage at each creep condition. The stress exponent of the minimum creep rate, n, increases from ~5 at lower stresses to ~10 at higher stresses at each temperature, and the value of n changes at the yield stress of the alloy. The activation energies for the creep, Q^sub c^, are determined to be 121 ± 10 and 162 kJ/mol, at lower and higher stresses, respectively. It is concluded that the creep of the diecast AM50 alloy is controlled by the high-temperature climb of dislocations, whereas the instantaneous plastic strain introduced by the higher stress of the creep test is assumed to cause the increased values of n and Q^sub c^. [PUBLICATION ABSTRACT]