Study On Interface Bonding And Wear Resistance Of SiC Foam Ceramic/Aluminum Matrix Composites

The three-dimensional structure foam ceramic/metal matrix composite is a co-continuous composite material.The ceramic phase and the metal phase cross-penetrate and continuously distribute each other,and the interface bonding strength is high.The composite material combines the advantages of high hardness,high wear resistance of the ceramic phase and good ductility of the metal phase,and has a wide range of applicationsIn this paper,SiC foam ceramic/205A composites were prepared by extrusion casting infiltration method.Interfacial bonding of it were studied by optical metallographic microscope,scanning electron microscope,X-ray diffractometer,X-ray energy spectrometer,digital Vickers hardness tester,electronic universal material testing machine,friction and wear testing machine and other modern materials analysis and testing methods.and tested the two basic mechanical properties of hardness and flexural strength as well as friction and wear properties.The preparation of SiC foam ceramic/205A composites with different porosity ceramic reinforcement phases was carried out.The interfacial bonding,solidification structure and interface element diffusion of composites were analyzed.The results show that when the liquid phase pouring temperature is lower than 750°C,the interface defects are more,and separation is easy to occur.780°C is the optimum pouring temperature.The SiC foam ceramics are tightly combined with the aluminum matrix material,and the voids and other defects disappear.The addition of ceramic reinforcing phase refines the grain of the aluminum matrix phase.The lower the porosity of the reinforcing phase,the finer the pore structure and the smaller the grain size in the solidified structure.The grain size of the small porosity composite near the pores larger porosity composites are opposite to those far away from the ribs;elemental diffusion exists at the interface of the composite and new phases such as Al₄C₃ and CuSiO₃ are formed;the interface of the foamed ceramic/aluminum matrix composite is a mechanical bond at the same time.A hybrid mechanism of elemental diffusion and interfacial reaction.The hardness and bending strength of the SiC foam ceramic/aluminum matrix composite were tested.The results show that the hardness of the composite material reaches 127.6HV,the aluminum matrix material is only 52.8HV,and the flexural strength of the composite material reaches 415.0MPa.The curved fracture has cleavage steps and river pattern features,and the overall appearance is brittle fracture.The wear resistance of composite materials and aluminum matrix materials was tested by changing the test parameters of load,time and speed.The results show that the wear resistance of the composite is not only stronger than that of the aluminum matrix,but also exhibits stable wear resistance under different friction conditions.The microstructure of the wear surface is analyzed.The results show that the existence of continuous ceramic phase will be aluminum.The severe adhesive wear and spalling wear of the matrix phase translates into lighter abrasive wear,which greatly improves the friction and wear properties of the composite,and provides a theoretical basis for its wear resistance.