| The main task of this paper is to research the manufacturing process of ZL104 alloy composites reinforced by SiC particles and the centrifugal casting process of composites has been studied too. The result indicates that the equipment and process are feasible. The particle is dispersive and well combined with the matrix alloy. The part formed by centrifugal casting has integrated figuration, dense microstructure and fine properties.According to the principle of manufacturing composite by mechanical stirring, a set of equipment for melting,stirring and gas protection has been designed, which is reasonable and convenient to handle. SiC particles are pretreated at 600℃before stirring. During the fusing, when fusion is at appropriate temperature, put the particle, which is preheated to 200℃, into it and immix the fusion and particle by the whirlpool made by the running stirrer. Adjust the position and stirring speed of the stirrer according to the fusion surface situation to assure the whirlpool is not too great, in order to reduce air immixture with the fusion and the oxidation of the matrix alloy. The rotate speed adopted in this research is 825r/min and stirring for 100 minutes stably. The composite is gravity-assist pouring into billets. The microstructure of the sample has been studied and analyzed. The result indicates that the aluminum matrix composite, with the weight of nearly 30kg, reinforced with small dimension (15μm) of SiC particles was manufactured, and the particles dispersed in the matrix uniformly and interface combined great.The disc-like part is formed in the metallic mould, which revolves at a high speed by centrifugal casting, with the prepared composites. The experiment shows that the fluidity of the composite is good, the formation ability is great too and the figuration of the part with slippery surface is integrated.The microstructure and air hole ratio of the parts have been analyzed. The result shows that the combination of the part formed by centrifugal casting is nice, structure is dense and the air hole ratio is reduced to 3% improved obviously comparing to the part formed by gravity-assist pouring. Choose three parts formed by centrifugal casting in same technology and two parts of them are heat treated by T5 and T6, separately. And then test their mechanical properties. The results show that solid solution and aging heat treatment improve the mechanical properties of the Aluminum matrix composite reinforced by particle. Tensile strength reaches to 182MPa after T5 heat treatment, which is higher than the part heat treated by T6, and improves greatly compared to non-heat treatment, which is 137MPa. Hardness of the parts changes in the same trend.The research shows that preparing the aluminum matrix composites by mechanical stirring and forming parts by centrifugal casting are available methods to research and extend the application of metal matrix composites. It is feasible to reinforce the aluminum matrix composites through heat treatment. |
