以真空等离子旋转电极雾化TA15钛合金粉末为原料,利用激光熔化沉积快速成形技术制备TA15钛合金板材。在α+β两相区内对合金进行退火热处理,研究热处理温度对合金组织、硬度及抗压强度的影响,分析了经不同温度退火后合金的断裂机理。结果表明:试样经两相区退火热处理后呈现出一种特殊的双态组织,初生α相的含量随热处理温度的升高而逐渐降低,且初生α片端的"叉形"形貌越来越明显;在两相区上部热处理后的试样,初生α相呈"竹节"状;试样的平均硬度值随热处理温度的升高变化不大,硬度值较稳定;试样的压缩强度对热处理温度的变化不敏感,断裂机制为延性断裂。因此,可通过在较大温区范围内调整热处理工艺来获得优异的综合力学性能。
The TA15 titanium alloy plates were prepared by laser melting deposition rapid prototyping technology using TA15 titanium alloy powder made by vacuum plasma rotating electrode atomization.The alloy was annealed at α +β two-phase region,the influence of annealing temperature on microstructure,hardness and compression strength was studied and the fracture mechanism of the alloy after heat treatment under different temperatures was analyzed.The results indicate that at two-phase region,a special bi-modal microstructure was found after heat treatment,the volume percentage content of primary α decreased slightly and the "forked" morphology became more and more manifest with annealing temperature increasing.The "bamboo-shaped" primary α was acquired when the annealing temperature was in the upper part of the two-phase region.The mean value of hardness shows stability under different annealing temperature.The compressive property is not sensitive to annealing temperature.The ductile fracture characterizes the fracture mechanism.Therefore,the excellent comprehensive mechanical properties can be obtained by adjusting the heat treatment process over a wider temperature range.