Ti-55531近β合金轧板拉伸性能各向异性研究

Research on the anisotropy of tensile properties of Ti-55531 near β alloy rolled plate

摘要:

Ti-55531针片状α组织在750_^oC热轧,通过分析微观组织及宏观织构研究了Ti-55531近β合金轧板塑性及极限抗拉强度的各向异性。结果表明,Ti-55531合金轧板内的α相垂直于受力方向分布,并且存在明显的α相织构。α相形貌的取向性使得沿轧向(RD)拉伸时的裂纹扩展阻力大于沿横向(TD)拉伸,从而具有更好的塑性。宏观织构造成沿RD和TD拉伸滑移系和孪晶的启动存在明显的差异,从而导致沿TD方向拉伸时具有更高的极限抗拉强度。

Abstract:

Ti-55531 alloy with the acicular α initial microstructure was hot rolled at 750_^oC. The anisotropy of ductility and ultimate tensile properties of Ti-55531 near β alloy rolled plate were studied by analyzing microstructures and macrotextures. The results show that the acicular α phases in the Ti-55531 alloy rolled plate are perpendicular to the direction of the force, and significant α macrotextures are appears. Due to the specific orientation of α phase morphology, the crack propagation resistance along rolling direction (RD) is higher than that along transverse direction (TD), which resulting in better ductility in RD. Macrotextures lead to obvious differences in the action of slip systems and twins along RD and TD, which results in higher ultimate tensile strength along TD.