Elastic and anelastic properties of C/Mg-2wt.%Si composite during thermal cycling

Ultrasonic technique is employed to detect microstructural changes induced in a carbon fiber-magnesium matrix composite (Mg-2wt.%Si alloy matrix reinforced by long unidirectional carbon fibers with volume fraction of about 30%) during thermal cycling in the range of 100-360 K through measurements of its elastic and anelastic properties. Variations of the elastic modulus of the composite during thermal cycling is largely determined by elasticity of the carbon fibers stressed by the thermally expanded/contracted matrix. Anelastic properties of the composite are caused by dislocation motion in the matrix.