TA5合金板材工艺对显微组织和力学性能的影响

研究了TA5合金板材的加工、退火及热矫形工艺对组织和力学性能的影响。结果表明:板坯第2火次锻造在相变点以上150℃变形,造成板材组织粗化,呈纤维状,强度非常高,塑性变化不大;换向轧制的板材组织均匀等轴化,再结晶晶粒尺寸增加,强度显著降低,塑性明显升高;随着精轧温度的升高,再结晶晶粒均匀化长大趋势明显,板材强度降低,塑性升高;为了避免热矫形过程对板材组织性能的影响,退火温度应高于热矫形过程中的料温;板材经过二次或三次热矫形后,不平度可达到(2~3) mm/m,室温力学性能基本不变。

Effect of Process on Microstructure and Mechanical Properties of TA5 Alloy Sheets

The effects of processing, annealing and thermal orthosis on microstructure and mechanical properties of TA5 alloy sheets are investigated. The results show that the slab deforms at 150℃ above the phase transition point during the second fire forging, resulting in the coarsening of the structure. The coarsened structure is fibrous and of very high strength, with little plastic change. The microstructure of sheets reversing rolled is uniformly exquiaxed, the size of the recrystallized grain increases, the strength declines and the plasticity rises obviously. With the increase of finishing rolling temperature, the homogeneous growth of the recrystallized grains is obvious, which reduces the strength and increase the plasticity. In order to alleviate the influence of thermal orthosis on microstructure and mechanical properties of the sheets, the annealing temperature shall be higher than that of the material in the thermal orthosis process. After the second or the third thermal orthosis, the unevenness can reach 2~3 mm/m, and the mechanical properties at room temperature are almost unchanged.