Structural Modeling And Damage Mechanism Of SiCp/Al Composites Under Tension And Compression

Particle reinforced metal matrix composites(PRMMCs)are widely used in automotive,electronics and aerospace industries because of their excellent wear resistance,high strength and high stiffness.Compared with the matrix alloy,the strength and stiffness of PRMMCs were significantly enhanced by the reinforced particles,but the plastic properties were decreased at the cost.Therefore,it is the research goal of this subject to study the effect of microstructure on macro-mechanical properties and fracture process of composite materials.The SiCp/Al composites with 30% particle volume fraction were studied in this paper.The matrix phase was ZL101 A aluminum alloy and the reinforced phase was SIC particles.The microstructure of the composite was observed and analyzed with the aid of optical microscope,and the parameters such as particle size and morphology were obtained.A two-dimensional model of multi-particle random distribution is compiled by MATLAB software,which can control the size of the model and the parameters of particle size,shape and volume fraction.The tensile and compressive properties of the composites were tested.It was found that the elastic modulus and yield strength of the composites were increased,but the plasticity was decreased.Based on the random distribution multi-particle model,the mechanical behavior and failure process of composites under tensile loading were predicted,and the effects of interface strength,particle strength,particle volume fraction and particle shape on the simulation results were studied.Studies have shown that an increase in particle volume fraction can increase the elastic modulus and yield strength of the composite,but reduce its elongation.The reinforcing effect of angular particles is stronger,but the stress concentration at sharp corners is more likely to cause particle fracture.The deformation process of composites under compressive loading was simulated,and the effects of particle shape and size,interface thickness and strain rate on the simulation results were studied.Studies have shown that small size particles have a better strengthening effect on composite materials.The interfacial thickness has little effect on the flow stress of the composite,but the increase of the interface thickness will lead to a more uneven stress distribution at the interface.With the increase of strain rate,the deformation hindrance effect of particles on the matrix is enhanced,the number of particle fractures increases,and the damage of the matrix appears in advance.