【摘要】 研究了热变形对TB18钛合金后续热处理过程中α相析出以及力学性能的影响。结果表明：通过双相区锻造工艺获得的圆棒，在其横截面上表现出均匀的成分分布。然而由于锻造工艺的特点，在横截面不同位置的变形程度不同。在锻造状态下，显微组织主要由β相基体和粗大不连续的初生α相组成。经过固溶处理和人工时效后，粗大初生α相消失，针状次生α相在基体中弥散析出。此外，时效后的样品中观察到分散的白色区域，经分析为次生α相未析出区域。尽管锻造后各个区域的成分分布均匀，但在锻造变形较小的位置，白色区域的含量更高，尺寸明显更大。这表明锻造变形不足抑制二次α相的析出，最终导致热处理强化效果降低。因此，与锻造工艺过程特征一致，样品沿着锻造圆棒的圆周方向，强度呈现周期性变化。更多还原

【Abstract】 The effect of hot deformation on α-phase precipitation during the subsequent heat treatment, as well as the mechanical properties of TB18 Ti-alloy, was investigated. Results show that the round bar obtained by the dual-phase field forging of the cast ingot exhibits uniform composition distribution on its cross-section. However, various degrees of deformation are detected at different positions on the cross-section, which is attributed to the characteristics of the forging process. Under the forging condition, the microstructure is mainly composed of β-phase matrix and coarsened discontinuous primary α-phases. After solution and following artificial aging treatment, the primary α-phases disappear, while needle-like secondary α-phases precipitate in the matrix. Additionally,dispersed white zones are observed in the samples after aging, which are analyzed to be the precipitation-free zones of secondary α-phase. Despite a uniform compositional distribution among various regions, these dispersed white zones exhibit higher content and larger size in the positions that have undergone lower forging deformation. It indicates that the insufficient forging deformation inhibits the precipitation of the secondary α-phase, ultimately resulting in the lower strengthening effect by heat treatment. Thus,consistent with the characteristics of the forging process, a periodic variation of sample in strength is detected along the circumferential direction of the forged round bar.更多还原