Numerical Simulation And Experimental Study On Mechanical Properties Of Aluminum Matrix Composites

Metal matrix composites with good mechanical properties are widely used in aerospace and other defense and military fields.In order to characterize the mechanical properties of aluminum matrix composites,Vickers hardness and uniaxial tensile test will damage the samples of aluminum matrix composites,which can not accurately predict and control the mechanical properties of aluminum matrix composites.It is impossible to measure the mechanical properties of aluminum matrix in aluminum matrix composites.In this paper,2024Al/Al₁₈B₄O₃₃w composite was selected as the research object.And the travel-load curve of the matrix was obtained by nanoindentation test.Through the nanoindentation test,the elastic modulus E and nanohardness H of the matrix material are 84.09GPa and 0.927GPa,respectively.The strain strengthening index,initial characteristic stress and initial characteristic strain of aluminum matrix were studied by dimensional method and inversion analysis method.The yield strength of aluminum matrix and power function elastic-plastic stress-strain relationship were determined.The yield strengthσand strain strength index n of aluminum matrix composites were 226.47 MPa and 0.224.Based on the obtained matrix mechanical performance parameters,a unit cell model was established and finite element simulations were carried out to explore the influence of different reinforcement shapes,volume fractions and sizes on the mechanical properties of aluminum matrix composites.The modified Eshelsy equivalent inclusion theory is adopted,the secant modulus and tangent modulus are introduced,and the volume fraction of the failure reinforcement is considered.The stress-strain curves of the aluminum matrix composites are respectively predicted,and the predicted curve is compared with the experimental tensile curve.Finally,the yield strength obtained by the tangent modulus method is 216.65 MPa,which is 12.8%lower than the yield strength obtained by the experiment.The yield strength of the aluminum matrix composite obtained by the modified tangent modulus method is about 249.23MPa,which is about 4.8%higher than the experimental curve,and the elastic modulus is 131.98 GPa.The multi-pass variable temperature hot rolling process of aluminum matrix composite sheet was analyzed by using Deform finite element software.The optimal hot rolling process is as follows:the first pass temperature is 450℃,and the lower pressure is 0.5 mm.The second pass temperature was 500℃and the lower pressure was 0.3 mm.The third pass temperature is 450℃and the lower pressure is 0.4 mm.