不同退火温度对Ti662钛合金组织演变和拉伸性能影响

Effects of different annealing temperatures on microstructure evolution and tensile properties of Ti662 titanium alloy

选取Ti662钛合金作为本文的研究材料,分析Ti662钛合金在不同退火温度条件下的微观组织与拉伸性能的演变规律,研究表明:Ti662钛合金在退火温度升高过程中,初生α相含量以及体积在组织中比例不断降低,而β转变组织的含量以及体积则不断增加,当达到单相区温度后,组织中出现三叉状晶界,且组织形成β晶粒,大量次生α相在组织中弥散分布。合金强度在退火温度为900℃时最低,但塑性最高,在退火温度为960℃时,合金强度达到最大值,塑性达到最小值。合金经两相区低温退火后,大量等轴状韧窝在断口中均匀分布,在退火温度接近相变点时,有明显的撕裂棱形貌出现在断口中,合金经单相区高温退火后,有类似于结晶状岩石形貌出现在断口中,且发现在断口中出现明显二次裂纹形貌。

Ti662 titanium alloy was selected as the research material of this paper,and Ti662 titanium alloy was heated at different temperatures,followed by annealing treatment.The study focused on understanding the influence of varying annealing temperatures on the microstructural characteristics and tensile strength of the Ti662 titanium alloy.The results showed that the examination demonstrated a persistent diminution in the content and volume of the primaryαphase within the Ti662 alloy,an observation concurrent with the escalating annealing temperature,while the content and volume ofβphase increased continuously.When the temperature reached the single phase re-gion,the trident grain boundary appeared in the structure,and the structure formedβgrains,and a large number of secondaryαphases were dispersed in the structure.The strength of the alloy is the lowest when the annealing tem-perature is 900 C,but the plasticity is the highest.When the annealing temperature is 960 C,the strength of the alloy reaches the maximum and the plasticity reaches the minimum.After the alloy is annealed in the two-phase region at low temperature,a large number of equiaxed dimples are evenly distributed in the fracture.When the annea-ling temperature is close to the phase transition point,there are obvious tearing edges in the fracture.When the annealing temperature rises to the single-phase region,the fracture morphology changes to a structure similar to crystalline rock,and it is found that there are obvious secondary crack morphology in the fracture.