Elastic and microplastic properties of Al–Si/Ge alloys obtained from levitated melts

Structure, density, Youngʹs modulus temperature dependencies as well as Youngʹs modulus and ultrasound damping as a function of vibration strain were studied for Al–Si and Al–Ge hypo- and hyper-alloys. Samples were obtained by fast cooling of a levitated melt. Aging of Al–Si alloy and recovery of Al–Ge properties were observed. These phenomena were explained by a transformation of bond type during formation of Si- or dissolving Ge-rich zones. Stress–strain curves of micro-deformation determined from acoustical tests and of macro-deformation by quasi-static bending tests were studied. Their concentration dependencies were explained by an effect of grain sizes of eutectic matrix and an effect of primary crystals.