Viscoelastic behaviour of eutectic composition and gamma phase of In-Sn alloys

ELIDA B. HERMIDA, DANIEL E. LÓPEZ, DIEGO G. MELO,

Buenos Aires

Conferencia; ICIFUAS 12; 1999

It is well known that damping of metallic materials increases at temperature aproximates the melting point. Consequently, low-melting-points alloys, such as In-Sn used in soldering of electronic devices, exhibit substantial viscoelasticity even at room temperature. From the practical point of view, there is particular interest in the mechanical behaviour of the $\beta$ and $\gamma$ phases. However, the as-cast microestructure of the In-Sn alloys depends on the substrate; particularly, In-Sn on Cu leads to regions of   $\gamma$ phase (In-rich).The aim of this work is to produce homogeneous sample of In-Sn alloys both at the eutectic composition and the $gamma$ phase in order to measure the temperature dependence of the internal friction of the samples. The morphological characteristic of the structute and the distribution of the $\beta$ and $gamma$ phases are determined by metallografhies. The elastic modulus and the internal friction of these alloys are measured with a composite oscillator at 50 kHz from 296 to 390 K. The anelastic and viscoelastic response is modelled in terms of grain-boundary dislocations.