Study On High Temperature Deformation Behavior Of 2024Al/Al₁₈B₄O₃₃w Composites

Metal matrix composites have been widely used in the fields of modern industry and national defense due to their excellent physical properties.However,the forging ability of composites is much lower than that of matrix alloys due to the addition of hard reinforcement,which seriously restricts its wide application.If the processing parameters are not properly controlled during the hot deformation process,the local deformation between the reinforcement and the matrix will not be coordinated.Then some defects,such as fracture,micropore gap,interfacial debonding and so on,will be produced.In order to avoid instability in the actual forming process,it is of great significance to establish reasonable machining parameters.In this paper,the hot deformation behavior of 2024Al/Al₁₈B₄O₃₃w composites prepared by squeeze casting were studied systematically by isothermal compression test.Firstly,the stress-strain curves of composites and matrix materials under different deformation temperature and strain rate were studied by isothermal compression test.The effects of deformation temperature,strain rate and other parameters on flow stress were analyzed,and the softening phenomenon of composites was explained.Secondly,the Arrhenius model based on phenomenological constitutive model and the BP neural network model based on artificial intelligence were constructed by extracting the flow stress data under different deformation of composites.The prediction accuracy of the two constitutive models for the thermal deformation behavior of composites was evaluated systematically.In addition,based on the three-dimensional hot processing map and neural network t hot processing map under different strain conditions,the machining safety and instability regions of composite materials were systematically analyzed by constructing the hot processing map under different instability criteria,and based on the three-dimensional hot processing map and neural network hot processing map under different strain states.By combining the microstructure evolution of field emission scanning electron microscopy and transmission electron microscope in the corresponding regions of the hot processing map and the temperature sensitive coefficient diagram,the accuracy of the hot processing map was verified.Finally,according to the processing parameters of the hot processing map and based on the deform-3D finite element simulation,the multi-direction forging hot working process of composite materials with different press amount,deformation temperature and processing passes conditions was analyzed.