An Investigation into the Effect of Zinc and Age Hardening Treatment on Impression Creep Resistance of Mg-5%Sn Alloy

In this article، the effects of adding Zn and conducting age hardening treatment on impression creep properties of Mg-5%Sn alloy have been investigated. The creep tests were carried out using impression creep method in which a cylindrical punch was used to apply the stress in range of 450 MPa < σimp < 270 MPa and at the test temperatures of 150، 175 and 200 °C. The results showed that age hardening treatment can make the distribution of Mg2Sn precipitates more uniform within the grains. Additions of 0. 6% Zn to the alloy improved its creep properties and this effect was attributed to the greater amount of precipitates formed on the non-basal planes and to their homogenous distribution in the microstructure. The values of stress exponent and activation energies determined in this investigation indicated that the pipe diffusion controlled by dislocation climb is the dominant creep mechanism for both Mg-5%Sn and Mg-5%Sn-0. 6%Zn alloys under the conditions used in this study.