GH4169高温合金高应变率本构关系试验研究

 基于高应变率下GH4169高温合金的本构关系是采用有限元法对GH4169高温合金进行切削加工数值分析研究的基础。本文针对GH4169高温合金,通过试验对其在温度为室温至1 000 ℃、应变率为2 000～10 000 s^-1的范围内的本构关系进行了研究。研究发现高应变率下GH4169高温合金的流动应力与塑性应变关系接近线性关系,同时温度影响着高应变率下应变率对本构关系的影响程度及方式。根据GH4169合金流动应力曲线的特点,对Johnson-Cook本构模型进行修正。基于试验结果,通过数据拟合确定了对应高应变率GH4169高温合金的材料常数,建立了描述GH4169高温合金高应变率下的本构模型,为切削加工有限元数值分析提供了理论基础,并为相关类似研究提供了思路。

Experimental Study of Constitutive Relationship of Superalloy GH4169 Under High Strain Rates

Finite element numerical simulation of the cutting of superalloy GH4169 is based on its constitutive model, which describes the relationship between stress and strain under high strain rates. In this paper, the constitutive relationship of superalloy GH4169 with temperature in the range from room temperature to 1 000 ℃ and strain rates in the range of 2 000-10 000 s^-1 is studied by experiments. The results show that the relationship between flow stress and plastic strain is close to linear relationship. Meanwhile temperature affects the degree and mode of the influence of strain rate on the constitutive relationship. According to the characteristics of flow stress curve of superalloy GH4169, the Johnson-Cook constitutive model is modified. Based on experimental results, the constitutive parameter values are determined by data fitting and a constitutive model of superalloy GH4169 is built. The work of this paper provides not only a basis for the numerical simulation of cutting superalloy GH4169, but also a useful reference for similar studies in future.