Creep and Creep-rupture Behavior of 2124-T851 Aluminum Alloy

摘要

High temperature creep and useful creep life behavior of Al-Cu-Mg (2124-T851 aluminum) alloy was investigated by conducting constant stress uniaxial ten-sile creep tests at different temperatures (473-563 K) and at stresses ranging from 80 to 200 MPa. It was found that the stress and temperature dependence of mini-mum creep rate could be successfully described by the power-law creep equation. The power-law stress expo-nent, n=5.2 and the activation energy for secondary creep, Q=164 kJ mol~(-1), which is close to that observed for self diffusion of aluminum (~140 kJ mol~(-1)). The observed values of n and Q suggest that the secondary creep of 2124-T851 aluminum alloy is governed by the lattice diffusion controlled dislocation climb process. A Monkman-Grant type relationship between minimum creep rate and time for reaching 1.5% creep strain is proposed and could be employed for predicting the useful creep life of 2124-T851 aluminum alloy.