Study On Deformation And Recrystallization Texture Of Ti-26 At.%Nb Alloy Sheet

?-type titanium alloy has good mechanical properties,corrosion resistance and biocompatibility,and its Young's modulus is significantly lower than a and ?+?-type titanium alloys,which can effectively reduce the implantation of the alloy into the human body due to its high Young's modulus The resulting stress shielding effect has broad application prospects in biomedical fields.? titanium alloy has good mechanical properties,corrosion resistance and biocompatibility.Its young's modulus is significantly lower than a and ?+? titanium alloys,which can effectively reduce the stress shielding effect caused by the high Young's modulus of the alloy implanted into human body.It has a broad application prospect in biomedical and other fields.In this paper,a typical non-toxic and harmless ? titanium alloy Ti-26 at.%Nb(hereinafter referred to as Ti-26Nb)was selected as the research object,and the alloy thin sheets with a thickness of 0.55 mm to 0.06 mm were prepared by the rolling method.Using metallographic microscope,X-ray diffractometer(XRD)and electron backscatter diffraction(EBSD)to study the evolution of deformation and recrystallization texture during the rolling and annealing of alloys,the following main conclusions were obtained:The evolution of deformation and recrystallization texture during rolling and annealing was studied by metallographic microscope,X-ray diffraction(XRD)and electron backscatter diffraction(EBSD).The main results are as follows:(1)The influence of cold rolling reduction on the deformation and recrystallization texture of Ti-26Nb alloy is closely related to the initial grain size.When the reduction is less than 55%,the deformation texture in the samples with large and small initial grain size is similar.When the reduction is increased to 65%,the favorable {001}<110>texture in the sample with small initial grain size is significantly enhanced,and the small initial grain size is more conducive to the optimization of deformation texture.When the reduction is less than 55%,the recrystallization texture in the samples with large and small initial grain size is similar.When the reduction is increased to 65%,the unfavorable {111}<112>texture in the samples with large initial grain size is significantly enhanced,and the large initial grain size is more conducive to the optimization of recrystallization texture.(2)The main modes of recrystallization nucleation of Ti-26Nb alloy are grain boundary nucleation and grain internal nucleation,and the shear band is basically not nucleated.In the early stage of recrystallization,the grains with specific orientation have no volume advantage,and the texture type is similar to that after complete recrystallization,which indicates that the alloy follows the mechanism of oriented nucleation in the recrystallization process.(3)The critical deformation of Ti-26Nb alloy was determined to be 8%?12%,and the critical rolling method was used to effectively reduce the {111}<112>recrystallization texture and enhance the {001}<110>recrystallization texture.The reason for the texture optimization is that during the critical rolling process,high Taylor factor {111}<112>grains obtained high strain energy storage,low Taylor factor {001}<110>grains obtained low strain energy storage,and subsequent annealing.During the process,the grain boundary moves to the high strain energy storage side.(3)The critical rolling reduction of Ti-26Nb alloy was determined to be 8%?12%.After the critical rolling treatment,the recrystallization texture of {111}<112>is effectively reduced and {001}<110>was enhanced.The reason for texture optimization is that the {111}<112>grains with high Taylor factor can obtain high strain-stored energy and the {001}<110>grains with low Taylor factor have low strain-stored energy during the critical rolling process,and the grain boundary moves to the side with high strain-stored energy during the subsequent annealing process.(4)Cross rolling has a significant effect on the deformation texture of Ti-26Nb alloy sheet.Within the range of 65%?88%reduction,a strong ? texture with peak at {112}<110>was formed by conventional rolling,and a more favorable strong a texture with peak at {001}<110>was formed by cross rolling.