Preparation And Study Of Lead Oxide Particles In Solid Phase Oxygen Control System Of LBE

Liquid Lead Bismuth Alloy(LBE)is used as nuclear coolant material and spallation target material for Accelerator Driven Subcritical System(ADS)because of its excellent physical and chemical properties.However,due to the corrosive effect of liquid lead-bismuth alloy on reactor steel,certain measures must be taken to prevent structural materials from being corroded under long-term operation of the reactor.Among them,controlling oxygen concentration in lead-bismuth alloy by gas or solid oxygen control method to form a dense oxide film attached to the surface of structural materials to prevent corrosion is the most commonly used method.Solid-state oxygen control method is very popular for its advantages of rapidity and safety,but there are a few studies on solid-state oxygen source lead oxide particles and their mechanical properties are low.Based on this background,a series of new lead oxide ceramics were prepared through experiments in order to prepare lead oxide ceramics with higher mechanical properties.On the basis of predecessors,this study improved the pressing process and innovatively added Bi2O3 powder to lead oxide powder as sintering aids.The relationship between the content of sintering aids and sintering temperature was discussed from density,hardness,strength,microstructure and phase analysis.By forming solid solution,the sintering process was strengthened and the mechanical properties were improved.According to the result of conventional sintering,the optimum ratio of samples was sintered by microwave.Then the mechanical properties were discussed from different angles,such as sintering temperature,sintering rate and holding time.The properties were compared with those obtained by conventional sintering,which provided a basis for the subsequent research of lead oxide ceramics.The results show that,under conventional sintering,the solid solution formed because of Bi2O3 and PbO powders strengthen the sintering process.The strength and hardness of Bi2O3-PbO ceramics increase markedly with the increase of the content of the sintering aids.With the increase of temperature,the strength and hardness of Bi2O3-PbO ceramics increase at first and then decrease.Among them,620?,3wt.%Bi2O3-97wt.%PbO ceramics have the best properties.Its hardness is about 4 times that of pure lead oxide ceramics,717 MPa.and its strength is about 2 times that of pure lead oxide ceramics.42.45 MPa.From the point of view of microstructure,when the content of Bi2O3 is 3 wt.%,the grain growth is more uniform and the voids are less.It was also found that microwave sintering can greatly shorten the sintering time,increase the density of ceramics.And it increases with the increase of holding time.The grain size is more uniform and smaller than that of conventional sintering.