A novel technique of mechanical spectroscopy for studies on metals in liquid and solid state

Mechanical Spectroscopy (MS) is a technique which allows to carry out internal friction and dynamic modulus tests on metals vs. temperature. MS has been extensively used for studying metals in solid state whereas few data on liquid metals are reported in literature and have been obtained by means of a modified inverted torsion pendulum. Present work describes a novel technique developed by us which permits to study metals from solid to liquid state without stopping experiments during solidification and melting. The metal is cast inside a container of stainless steel (AISI316) dosed at an end; after solidification the open extremity of the reed has been sealed. The container-metal system is mounted in free-damped mode and excited by flexural vibrations. Experimental data (damping Q' and dynamic modulus E) are corrected from the contribution of the container. This technique has been used for studying precursor phenomena of melting in pure metals and alloys and liquid-liquid transitions in several alloys.