MECHANICAL DYNAMICAL SPECTROSCOPY IN CU-LI ALLOYS PRODUCED BY ELECTRODEPOSITION

Cu-Li alloys obtained by electrodeposition were studied by means of th e mechanical dynamical spectroscopy (MDS) technique (also called mecha nical spectroscopy), which consists of the simultaneous measurement of the damping and the elastic modulus as a function of temperature. In this work MDS measurements were performed as a function of temperature . Also the strain amplitude dependent damping behaviour was studied. T he damping spectrum of pure copper as a function of temperature shows low and the intermediate temperature grain boundary damping peaks at a pproximately 500 and 750 K respectively. It should be pointed out that , in the Cu-Li alloys a new peak at 625 K was found. This new peak cou ld be the result of two physical effects, which are overlapped. The fi rst effect would be a peak owing to the melting of the Cu 18 at.% Li c rystals and the second effect would be a peak owing the the Zener's pa ir reorientation mechanism. The influence of the thermomechanical stat e of the samples before being electrodeposited was investigated, and t he changes in the MDS spectra, measured during heating and cooling wer e also investigated.