轧制工艺对TC20钛合金小规格棒材组织和力学性能的影响

Effect of Rolling Techniques on Microstructure and Mechanical Properties of TC20 Titanium Alloy Small-size Bar

采用两种轧制工艺制备了TC20钛合金Φ13.5mm小规格棒材,利用光学显微镜和万能拉伸试验机分析不同轧制工艺对TC20钛合金小规格棒材的组织与力学性能的影响。结果表明:两种轧制工艺制备的棒材组织分别为典型的双态组织和等轴组织,等轴组织的拉伸变形时在α相个别晶粒中以滑移开始的,在合金断裂前可产生很大的变形,从而获得较高的塑性;而由少量初生α相和大量细小弥散的次生α相的双态组织,引起的弥散强化效果更明显,在变形过程中易形成应力集中,因此,棒材的抗拉强度和屈服强度较高;两种轧制工艺制备的棒材组织均符合ETTC2中A1~A9的要求。

The TC20 titanium alloy Φ13.5mm plates was prepared by Two rolling techniques,The effects of different rolling techniques on the structure and properties of TC20 titanium alloy small-size bars were analyzed by optical microscope and universal tensile testing machine.The results show that the microstructures of the bars prepared by the two rolling processes are typical dual-state microstructures and equiaxed microstructures.The tensile deformation of equiaxed microstructures starts as slippage in the individual grains of the α phase before the alloy fractures.A large amount of deformation can be produced,thereby obtaining higher plasticity;and a small amount of primary α phase and a large number of small and dispersed secondary α phases of the two-state structure,the dispersion strengthening effect is more obvious,and stress concentration is easy to form during the deformation process.Therefore,the tensile strength and yield strength of the bar are high;the structure of the bar prepared by the two rolling processes meets the requirements of A1~A9 in ETTC2.