Estudo do processamento termomecânico de liga experimental de zircônio e seu efeito nas propriedades mecânicas e formação de hidretos

Abstract

Zirconium alloys are used in components of nuclear reactors, particularly in the fuel element, for their excellent properties of corrosion resistance, mechanical resistance, thermal conductivity and low neutron absorption. The interaction with hydrogen during the operation of the reactor leads to the formation of hydrides, dependent on the presence of crystalline discontinuities and on the texture of the material. This work aimed to validate the thermomechanical processing of an experimental zirconium alloy produced at COPPE, as well as to investigate its effects on the microstructure, on texture and on the precipitation of hydrides in the material. The alloy was processed by two thermomechanical routes, leading to a recruited and a recrystallized condition. The samples were hydrogenated and characterized by tensile tests, scanning and transmission electron microscopy and hydrogen permeation assay. The results showed the adopted processing viable for the production of thin plates, generating texture with presence of (0001)<uvtw> components and good orientation of hydrides after hydrogenation. The recrystallized condition has been shown to be more promising concerning the mechanical properties than the corrugated condition.