3J21合金简化本构关系的建立及其纳米压痕试验

为进一步研究3J21合金在塑性成形过程中的微观组织演变规律和强化机理,结合3J21合金在电子万能材料拉伸试验机上进行单轴拉伸试验所得的数据,建立了以应变ε和应变硬化指数n为基本参数的3J21简化Johnson-Cook本构关系方程。借助3J21合金的纳米压痕试验,测定该合金的弹性模量,并利用所建的本构关系方程对纳米压痕试验进行有限元模拟,模拟结果和压痕试验所得的载荷-压深曲线有较好的吻合。建立的简化本构关系可较好地描述3J21合金在常温准静态应变率试验条件下的应力应变特征。

Establishment of Simplified Constitutive Relationship for 3J21 Alloy and Its Nano-indentation Test

For further study the microstructure evolution law and strengthening mechanism of 3J21 alloy during plastic forming process ,combined with the experimental results of uniaxial tensile tests carried out on the universal tensile testing machine ,the simplified constitutive relationship model using the strain and strain hardening index as the primary variables was established. The Young′s modulus of the material was determined based on the experimental results of nano-indentation tests. By using the constitutive relation model,the finite element simulation of the nano-indentation was carried out. Good agreement was found between the load-depth curves obtained from the two methods. The equation could well describe the stress and strain characteristics of the alloy under the test conditions of quasi-static state at room temperature.