Research On Deformation Texture Of Nb/Zr Composites Processed By Accumulative Roll Bonding

Metal laminated composite is a new composite material that combines two or more than two metals with metallurgical technology by combining technology.Metal laminated composites are laminated by dissimilar metals,not heterogeneous metals.So the metal laminar composites can still maintain their own properties.The advantages of each component are combined to make up for the inadequacy of each component.The laminated metal composite has excellent properties which are difficult to be matched by a single metal or alloy.Two kinds of Nb/Zr multilayer metal composite plates were prepared by Accumulative Rolling Process.The initial metal Nb,Zr single layer thickness is 1mm,The single layer thickness of initial metal Nb is 1 mm,and the single layer thickness of Zr is 2 mm.The two kinds of composite plates are taken as the research objects,The microscopic deformation mechanism of HCP superimposed rolling material is mainly studied.X ray diffraction(XRD)is used to obtain the distribution and evolution of the texture of the Nb/Zr multilayer metal composite plate.Scanning electron microscope(SEM)and energy spectrum analyzer(EDS)are used to obtain the micrograph of the side rolling surface of the cumulative rolled Nb/Zr composite plate and the line scanning composition analysis.The macroscopic mechanical properties of the cumulative rolled Nb/Zr composite plate were obtained by the electronic universal tensile test machine.Microstructural morphology of cumulative rolled Nb/Zr composite plates was obtained by transmission electron microscopy(TEM).The mechanical properties of Nb/Zr composite plate prepared by cumulative rolling are good,With the increase of stacking pass,the tensile strength and yield strength of Nb/Zr multilayers increases,and the plasticity of the composite plate first decrease and then increase.The Nb layer and the Zr layer of Nb/Zr composites are well bonded by the observation of SEM.With the progress of the accumulative roll bonding process,the Zr layer is prior to neck,fracture or even separate.This is caused by a shear band that penetrates the heterogeneous interface during the deformation process.The dislocation cells in the Nb and Zr layers of the composite plate obtained by the accumulative stacking and rolling are mainly dislocated cells with dislocation cells with a size of about 300 nm,high density dislocations between dislocations and low intracellular dislocation density.The submicron-scale dislocation cellular structure inside each metal in the composite plate ensures that the composite plate still has good plastic deformation capability while having higher strength.The texture of Zr at the interface of the intermediate thickness of Nbl mm/Zrl mm composite plate and Nbl mm/Zr2 mm composite plate shows a consistent change rule,which is different from that of the pure metal Zr.With the increase of stacking pass,the bimodal texture of the {0001} basal plane of the Zr layer tends to weaken at the middle thickness of the composite plate,which is also the reason that the Nb/Zr composite plate still possesses strong plastic deformation ability.The cubic structure of Nb at the intermediate thickness of the cumulatively rolled Nbl mm/Zrl mm composite plate decreases with the increase of the lapped rolling pass number,but differs from that of pure Nb in rolling texture.However,for the cumulative rolling Nbl mm/Zr2 mm.The cubic texture of Nb at the middle thickness of the composite plate increases with the increase of stacking pass,which is similar to that of pure Nb.For Nbl mm/Zrl mm composite plate and the Nbl mm/Zr2 mm composite plate.The texture of Zr and Nb at the interface of the middle thickness shows different rules.This indicates that the heterogeneous interface has some influence on the deformation structure and texture of the metal in the composite,and the influence of the elemental layer thickness on the deformation of the metal deformation is also different.