基于经典塑性理论的新型亚稳β钛合金热变形粘塑性统一本构模型

Viscoplastic Unified Constitutive Model for Metastable β Titanium Alloy Based on the Classical Plasticity Theory

摘要:

对含动态回复(DRV)、动态再结晶(DRX)的钛合金热变形本构模型进行了研究。其中基于经典塑性理论和内变量粘塑性统一本构理论构建模型的思想，在两者相关点的基础上，结合材料的变形特性，通过对相关表达式的具体推导，构建了相应的本构模型，模型物理意义清晰。最后将模型应用于预测新型亚稳β钛合金Ti2448的热变形流变行为。根据所建模型得到的预测曲线和实验曲线吻合较好，能够有效预测该合金在热变形过程中的流动应力。本研究所建本构模型是有效的，构建方法是合理的，能为构建亚稳β钛合金热变形本构模型提供一种有效的方法。

Abstract:

The constitutive model for titanium alloy was researched to describe the dynamic recovery (DRV) and dynamic recrystallization (DRX) behavior during hot deformation. During this process, based on the constructing method of classical plasticity and viscoplastic unified constitutive model using internal state variables, the constitutive model was developed considering the deformation mechanism of materials by deriving the correlative relations. The proposed model is able to offer more clearly physical insight. At last, the deformation behavior of a new kind of metastable β Ti2448 titanium alloy was described by the proposed model during hot deformation. The stress-strain curves predicted by the developed constitutive model well agree with experimental results, which confirms that the developed constitutive model can give an accurate estimate of the flow stress of Ti2448 titanium alloy. The developed model is effective, the method is reasonable and it can provide an effect method to model the flow behavior of metastable β titanium alloys during hot deformation.