Zhenhong Wang

Hydrogen absorption–desorption properties of UZr0.29 alloy

Hydrogen absorption–desorption properties of the UZr0.29 alloy and uranium metal were investigated in detail at hydrogen pressures as high as to 0.4 MPa and over the temperature range of 300–723 K. Both UZr0.29 alloy and uranium metal showed similar hydrogen isotopic effect and hysteresis effect. UZr0.29 alloy absorbed hydrogen (deuterium) up to 2.3H (2.18D) atoms per F.U. (formula unit) by only one-step reaction and hence each desorption isotherm had a single plateau over nearly the whole hydrogen composition range. The UZr0.29 alloy showed a little lower dissociation pressure than that of pure uranium; however, it exhibited high durability against powdering upon hydrogenation and may have good heat conductivity. The UZr0.29 hydride has the potentiality to substitute pure uranium hydride as a material for tritium treatment and storage.

Effect of strain rate on fracture of U-5.5Nb alloy

ABSTRACT The microstructure and tensile properties of an aged U-5.5u2009wt-% Nb alloy have been experimentally investigated with the aim of obtaining the influence of strain rates on fracture behaviour. The result shows that strain to failure is sensitive to strain rate and decreases with an increase in the strain rate. Fracture surface analysis indicates that the alloy exhibits a typical ductile fracture. Two types of carbides (niobium carbide and uranium carbide), mainly distributed at the grain boundary, are confirmed, which participate in the process of fracture and are involved in different void nucleation mechanisms during the final ductility fracture. Namely, niobium carbide tends to generate voids by debonding with the matrix, while uranium carbide is more likely to experience cracking.

Preparation and Characterization of Ni+Zn Composite Coating on U–Ti Alloy

Uranium and uranium alloys are a kind of important nuclear materials with unique physics and chemical properties. Unfortunately, it is eroded easily, especially in humid environment. In this paper, Ni coating and Ni+Zn composite coating were prepared on the surface of U–Ti alloy. The adhesion strength, phase structure and corrosion properties were characterized by tensile method, X-ray diffraction and electrochemical methods. The results showed that the Ni coating was a face centered cubic structure, while the anodic Ni+Zn composite coating was hexagonal structure. The average adhesion strength of composite coating was 16.0 MPa. The corrosion protection of composite coating was mainly due to the electrochemical protection of Zn coating and the physic barrier function of Ni coating.