Research On Powder Metallurgy Fabrication Of SiCp/Sn/Al Composites And Their Properties

SnO2was coated onto the surface of SiC particle by chemical deposition method.SiC particulate reinforced pure aluminum composite was succeffully fabricated bypowder metallurgy technique. The microstructure of the composite and the interfacicalbehaviour were studied by use of XRD、DSC、OM and SEM. The compressionproperties at high temperature of the composites were studied. SiCp/Sn/Al compositerods were obtained through hot extrusion at450℃which agreed with the optimumdeformation parameters obtained by high temperature compression deformation. Andthe compression properties and the frictional wear test of the as-extruded materials werestudied.The analysis of XRD、DSC、OM and SEM showed that a chemical reactionexisted between SnO2coating and aluminum during sintering process,product of thereaction was Sn. The interface bonding strength of the composite can be improved byappropriate interface.The fabricated composites were tested and the results indicated that the hardness ofthe composite increased with the Sn content increasing. The compression test showedthat the flow stress and elastic modulus of the composite decreased slightly with the Sncontent increasing. Results of the high temperature mechamical of SiCp/Sn/Al showedthat as the demineralization of matrix and liquid Sn which reduced the reinforcementeffect of particulate, two of them result in the flow stress during the compressiondeformation decreased with the increase of Sn content, and reduced when thetemperature increased and strain rate decreased.After extrusion, the hardness and flow stress of composite were increasedsignificantly. The frictional wear test showed that the wear amount of compositesincreased with the sliding rate and load, and firstly decreased then increased with theincrease of the percentage of the SiC paticles. The friction coefficient of compositecoated with Sn was stable. Wear morphology showed that the dominant wearmechanism was slight adhesion behavior at low load and low speed, and abrasive wearat high speed and high load.