MECHANICAL ENERGY LOSSES IN SINGLE CRYSTALLINE MOLYBDENUM. ITS RELATION WITH MICROSTRUCTURE

G. I. ZELADA-LAMBRI; P. B. BOZZANO; O. A. LAMBRI; C. L. MATTEO; P. A. SORICHETTI; J. A. GARCÍA

Rosario

Congreso; 10th Congreso InterAmericano, Congress of Electron Microscopy 2009, CIASEM 2009; 2009

CIASEM

Molybdenum and its alloys are used in nuclear reactor vessels and other reactor components, detectors in control systems of Tokamak devices and recently they have attracted interest as components for the development of space nuclear reactor power systems. The temperature range around 0.3 Tm (≈ 865K), usually related to the stage V of recovery, is particularly interesting in molybdenum due to the strong influence on the mechanical properties both in the pure metal, as in technological molybdenum based alloys. In fact, neutron irradiation in molybdenum at temperatures below 1000K followed by annealing at temperatures higher than473K, lead to the increase in the yield stress, the ultimate tensile strength and the ductile-brittletransition temperature. At annealing temperatures within the stage V (>900K), the yield stressand the UTS begin to decrease.In this work we have related the results of both mechanical spectroscopy (MS) also referred to as the internal friction method or damping measurements in early literature, and transmission electron microscopy (TEM), obtained in deformed and neutron- and electron-irradiated molybdenum single crystals. Indeed, our aim is focussed in to investigate the interaction processes between dislocations and point defects; from room temperature (RT) up to 30% of the melting temperature (0.3Tm).