The microstructure and impression creep behavior of cast Mg-4Sn-4Ca alloy

Because of low creep properties of magnesium-aluminum alloys, magnesium-tin alloys have received much attention in applications where high mechanical properties in high temperatures required. In this study creep properties of Mg-4Sn-4Ca alloy were investigated by the aim of impression creep test, scanning electron microscopy, energy dispersion spectrometry and X-ray diffraction analysis. The impression creep tests were carried out under different shear modulus normalized stress at high temperatures. According to the measured stress exponent values and activation energies the climb-controlled dislocation creep was determined as the dominant mechanism. The creep resistance of this alloy was related to the presence of Ca-Mg-Sn and Mg2Ca phases which are distributed uniformly in the matrix and exhibit high thermal stability. (C) 2015 Elsevier B.V. All rights reserved.