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

On the basis of the original characteristics of metal materials,metal layered composites could have the physical,chemical properties and mechanical properties that single metal do not have.It is expected to have high strength,high stiffness,seismic,light and other performance requirements and have advantage of low cost,wide application.In this paper,two kinds of Ti/Zr multilayers were prepared by the accumulative roll bonding process:the initial metal Ti and Zr is 50 ?m in thickness,and the initial thickness of Ti and Zr is 1 mm in thickness.X-ray diffraction(XRD),scanning electron microscopy(SEM),tensile testing machine and transmission electron microscopy(TEM)were used to study the texture evolution and distributionion,macro-mechanicalproperties,macroscropic lamellar structures and microstructure.The Ti layer and the Zr layer of Ti/Zr composites are well bonded by the observation of SEM.With the progress of the accumulative roll bonding process,the Ti layer is prior to neck,fracture or even separate.In the Ti/Zr composites,there are several shear bands through several layers.By EDS and XRD results,it can be seen that in the Ti/Zr composites,only the intermetallic diffusion of the constituent metal atoms occurs at the interface of the two metals and the intermetallic compounds are not produced.This indicates that the process of 300?and 575? intermediate annealing in this scheme does not produce intermetallic compounds in the composites,which reduces the interference of the intermetallic compound to the mechanical properties of the composites.The mechanical properties of pure Ti,Zr and Ti/Zr composite plates show that the Ti/Zr multilayers have higher strength than pure Ti and Zr,and the plasticity is lower than that of pure metal Ti and Zr.With the increase of stacking pass,the tensile strength and yield strength of Ti/Zr multilayers increases,and the plasticity of the composite plate decreases.But the third cycle Ti/Zr composite still shows better plasticity with elongation of 20%.The TEM analysis of Ti layer and Zr layer of the third cycle Ti/Zr composite shows that some grains of Ti layer and Zr layer have a large number of dislocations but some almost have no.And the grain size of Ti and Zr is nanometer scale.It is this mixed structure that Ti/Zr composite could be with higher strength and good plasticity.The analysis of the XRD texture determination shows that the main texture of pure Ti is {0001} basal doule-peak texture.But,with the increase of cycles,there is a significant{11(?)0}<(?)010>texture in addition to the {0001} basal doule-peak texture in the Ti layer.The intensity of {11(?)0}<(?)010>texture increases while the intensity of {0001} basal doule-peak texture decreases with the increase of cycles.But,{11(?)0}<(?)010>texture of cold rolling Ti does not change with increase of reduction in cold rolling.The main texture of pure Zr is{0001} basal texture.But,with the increase of cycles,there is also a significant{11(?)0}<(?)010>texture in addition to the {0001} basal texture in the Zr layer.The intensity of {11(?)0}<(?)010>texture does not increase with the increase of cycles like Ti.But,{-120}<{(?)010>texture of cold rolling Zr does not change with increase of reduction in cold rolling.The reason for the appearance of the abnormal texture is attributed to the fact that the stress accumulation at the hetero-interface in the multi-layer composites triggers the shear band activation within the component metals.