Finite Element Simulation Of Aluminum Alloy/polyether Ether Ketone (PEEK) Hot Pressing Connection

In the context of lightweight,aluminum alloy/polymer composite is a good alternative material for metal parts,and heterogeneous materials can be connected in a variety of ways,among which the hot pressing connection is simple and reproducible,but it is difficult to observe the polymer filling phenomenon in the process of hot pressing connection in real time.This paper used Ansys Workbench software to simulate the hot pressing process of aluminum alloy/polymer,and studied the influence of aluminum alloy surface structure,temperature and pressure on the polymer filling state.Firstly,the pressure bearing capacity of aluminum alloy substrate with trapezoidal,circular and cylindrical surface structures was analyzed.The base plate model was simplified based on the actual working conditions,and the aluminum alloy base plate model with nine support units in a group was retained.The spacing of each support body was the same,all of which were 0.3mm.Under the unit area,the bearing capacity of the surface structure is cylinder,trapezoid and round table from high to low.Under the condition of high temperature,when the pressure is greater than 15 MPa,the surface structure of aluminum alloy is deformed,and the deformation and stress concentration appear near the root of the support body.Secondly,the viscosity of polyether ether ketone(PEEK)was described by the Cross-WLF model,and the viscosity model was written by the user defined function(UDF).The filling simulation of PEEK hot pressing process was carried out by the method of fluid volume VOF.The influence of hot pressing parameters of temperature and pressure on the filling condition was mainly studied.Finally,it is concluded that the optimal hot pressing parameters are 450℃temperature and 10 MPa pressure.When the hot pressing temperature is 450℃ and the pressure is 10 MPa,the PEEK melt is basically completely filled into the support body void.With the increase of temperature,the PEEK viscosity decreases and the filling effect improves,the simulation results are in agreement with the experimental verification.With the increase of pressure,the filling efficiency is improved.In the process of PEEK filling,the viscosity in the middle of melt was high and the viscosity at the entrance of filling channel was low.The Angle of filling flow channel with different surface structures affects the filling quality.The larger the Angle,the better the filling effect,and the sharp Angle formed by the root and bottom of the support body is easy to appear filling defects.The simulation results show that the surface structures with strong to weak filling effect are cylinder,trapezoid and round platform.In the shear strength test of aluminum alloy /PEEK composite plate with different surface structures,the trapezoidal composite plate has the highest shear strength(up to 83MPa),followed by the round platform(64.4MPa),and the cylinder has the worst shear strength(only 48.5MPa).