Decomposition of the meta stable phase γ(U, Mo, Pt) to 480oC

The fuel with low enrichment of U for experimental reactors and radioisotopes production it demands, to compensate the smallest activity, the development of technologies for obtaining new alloys that facilitate to increase the density of the U. The aggregate of Mo to U it allows to retain in form meta stable, to relatively low temperatures, the cubes phase γU of high temperature that represents the more acceptable properties to be part of the fuel. The contribution of small quantities of transition elements provides an elements production additional stabilization effect. In this work we study the effect of the platinum. The U-7%Mo and U-7%Mo-0.9%Pt (in weight compositions) alloys were studied. They were manufactured in an arch furnace and later on were homogenized in composition during 2 h to 1000oC. Iso thermic treatments were carried out to 480oC with variable durations between 1 h and 30 h. Decomposition of the meta stable γ phase was studies by means metallographic and x rays diffraction analysis. The main conclusions are that the platinum attach substantially retards the beginning of the decomposition of the γU phase and, for both alloys, an important dependence is observed with the size of grain γ initial (IE)