TWO METHODS FOR THE CONSTITUTIVE MODELING OF TIB2/7050 AL COMPOSITES

In this paper, the Johnson-Cook constitutive model of in situ TiB2/7050 Al metal matrix composites determined by two different methods are compared. The commonly used quasi-static and dynamic compressive experiments are firstly conducted under the strain rate range of 10(-3)similar to 5000s(-1) and temperature range of 20 similar to 200 degrees C. The orthogonal cutting experiments are also used to calculate the JC model. The description ability of two models are evaluated by two statistical parameters: correlation coefficient and average absolute error. The results show that the JC model determined by the compression experiments performs better to describe the stress-strain behavior of in situ TiB2/7050 Al composites. Although the JC model from orthogonal cutting experiments can be used to simulate the cutting process, it cannot describe the flow stress behavior exactly during material deformation processes. For an accurate constitutive model of a material, the basic tensile or compression test is deemed necessary.