Effect Of Secondary Cold Rolling And Annealing On Microstructure And Texture Evolution Of Commercially Pure Titanium

In this paper,hot rolled and annealed industrial pure titanium TA1 sheet was used to carry out experiments of different pretreatment followed by secondary cold rolling and annealing.The influences of initial orientation,pre-cold rolling deformation,pre-annealing temperature and rolling distribution on microstructure and texture evolution of pure titanium sheet during cold rolling deformation and annealing were studied by back scattering diffraction(EBSD)technique and tensile test.The research results show that:The effect of initial orientation on mechanical properties,texture composition and r value of TA1 sheet was studied by uniaxial tensile test and texture analysis.The initial samples with higher Basal Tilt texture components show higher yield strength and tensile strength in the tensile test,while lower elongation.As for the initial samples with more Basal Scatter components,they have better elongation in the process of tensile deformation while lower yield strength and tensile strength.Basal Scatter texture component's influence on the r value is the largest,the second is the Basal TD and <101?0>//RD texture components,and the Basal ND texture components minimal effects on r value.Then,the effect of pretreatment process on the microstructure and texture composition of the TA1 plate was compared and studied by EBSD method.Low annealing temperature(550 ?)or pre deformation is small(30%),the sample after cold rolling to produce less of a compression stretching twin twin and time;The secondary tensile twins can be found in cold rolled samples with medium to large pre-deformation.After high-pre-deformation samples were pre-annealed and cold-rolled at high temperature,the compression twins were firstly generated in the grain near the ND of axis c,and then the secondary tensile twins were generated in the primary compression twins,resulting in the enhancement of the Basal ND texture components.Finally,the effect of rolling distribution on microstructure and texture evolution of hot rolled annealed TA1 sheet was studied.The above four rolling allocation amount samples in same annealing conditions its orientation angle distribution located 15-30° and 70-80°,there are two broad peak between respectively by the grain coarsening and anisotropy.the secondary annealed samples with 30% pre-deformation and the annealed samples with 85% has the highest estimate r value;the forecast r value of the secondary annealed samples with 70% pre-deformation is lower;the estimated r value of the secondary annealed samples with 50% pre-deformation is the lowest.