The Numerical Simulation Research On Tube Extrusion Forming Technology Of Glass/Aluminium Metal Matrix Composites

Glass/Aluminium Metal Matrix Composites is a new type of green material, This material has the both advantages of aluminium and reinforcement partices(glass).In this dissertation, the high temperature compressive deformation behavior of Glass/Aluminium Metal Matrix Composites was performed using Gleeble-1500 thermal simulator.Through isothermal compression experiment,we have had a systematic study on the forming properties of Glass/Aluminium Metal Matrix Composites material.The deformation temperature,deformation rate,and deformation extent are analyzed emphatically which affect thermal deformation flow stress of material. Through numerical simulation of finite element method(FEM), the extrusion course of the tube is simulated, then discussed the mold structure and process parameters during the extrusion forming process. The main research findings and new outlooks are as follows.1. A near steady plastic flow of the Glass/Aluminium Metal Matrix Composites was confirmed during isothermal compression deformation in the range of 573K-723K and 0.01s-1～10s-1.The flow stress increases with decreasing of deformation temperature and increasing of strain rate.2. At the strain rate of 10s-1 the true stress-strain curves exhibit oscillations apparently,this indicate that dynamic recrystallization can be happen,though there is the high stacking fault energy for Glass/Aluminium Metal Matrix Composites.3. The flow stress of the composites during high-temperature deformation can be described by Zener-Hollomon parameter: and4.The math model is coupled into MSC.Superform which reflects the relations between the material resistance and technologic parameter.We take the extrusion process of the tube as an example, and adopt rigid-plastic finite element method to study how the forming technology parameters influence the equivalent strain, equivalent stress and the load-position curve, which provides a theory and technology support for optimizing extrusion of Glass/Aluminium Metal Matrix Composites tube. Through comprehensive analysis of extrusion process, the best forming conditions is at temperature673K, at deformation rate 1mm/s, at cone angle 45°and with 0.2 friction coefficient.