Zirconium alloy has the characteristics of very low thermal neutron capture cross section, excellent corrosion resistance and high temperature creep resistance, and is widely used in nuclear reactors, such as pressure tubes and nuclear fuel cladding. With the development of nuclear energy towards high efficiency and high safety, higher requirements have been put forward for the mechanical properties, radiation resistance, thermal stability, creep resistance and corrosion resistance of nuclear zirconium alloys. In recent years, metal interface materials have gradually become a research hotspot. A large number of studies have shown that the interface in the material can effectively hinder dislocation motion to improve the material strength. At the same time, the interface can be used as an absorption trap to effectively reduce radiation damage. In addition, the stable interface energy in the material is lower, and it often has better thermal stability. If a large number of interfaces can be introduced into the zirconium alloy, its comprehensive performance will be improved. However, the metal-layered materials prepared by prior art have many shortcomings, such as single interface orientation, anisotropy of mechanical properties, weak interface bonding and poor plastic deformation. Therefore, it is of great significance to develop and fabricate large multistage 3d nano-layered zirconium alloys.
Introduced through in front of the phase change fast deformation increases in a nuclear site density method to refine the organization, developed a multi-level three-dimensional nano layered double phase zirconium alloy, the alloy group including several microns of coarse grain, coarse grain contained in micron level with different space to LAN parallel lamella organizations, at the same time, the parallel plate by a large number of nanoscale layers of HCP zirconium and zirconium BCC. Compared with the zirconium alloy with thick lamellar structure which is not obtained by rapid deformation at high temperature, the multistage 3d nano-layered bipolar zirconium alloy has finer lamellar thickness and higher interface density. The results of mechanical properties test show that multistage 3d nano-layered bi-phase zirconium alloy has the advantages of high strength, high hardening rate and high ductility.
It was found that: at the initial stage of deformation, before the macroscopic yield of the sample, a large number of single preferred cylinders dislocations were initiated in HCP zirconia, and the two-phase interface could effectively hinder the dislocation movement and promote the dislocation to plug at the interface to improve the back stress.
