Dislocation dynamics in molybdenum in the temperature range around 0.3 of the melting temperature

G. I. ZELADA-LAMBRI; O. A. LAMBRI; P. B. BOZZANO; G. J. CUELLO; J. A. GARCÍA; C. A. CELAURO

Buenos Aires, Argentina

Congreso; 9° Congreso Internacional de Metalurgia y Materiales, Sociedad Argentina de Materiales-Sociedad Chilena de Metalurgia y Materiales (SAM-CONAMET) 2009. Priemras Jornadas Internacionales de Materiales Nucleares; 2009

Sociedad Argentina de Materiales

The dislocations dynamics in deformed and neutron irradiated single crystalline molybdenum has been studied by means of mechanical spectroscopy in the temperature range between room temperature and 1273K. The behavior of the arrangements of defects agglomerates and dislocations has been determined, as a function of temperature, using transmission electron microscopy and small angle neutron scattering. Furthermore, electrical resistivity and differential thermal analysis were also used in order to obtain thermodynamic information about the state of the microstructure in the studied temperature range. The analysis of the damping spectra, from mechanical spectroscopy measurements, gave rise to find two different interaction processes between dislocations and points defects, depending of their temperature of appearance. In fact, the physical mechanism which controls the damping peak at around 800K and thereof the movement of dislocations at these temperatures, was related with the dragging of jogs by the dislocation under movement assisted by vacancy diffusion. However, at higher temperatures of about 1000K, where the high temperature peak appears, the dislocations dynamics was more consistent with the formation and diffusion of vacancies assisted by the dislocation movement.