Research On Preparation And Microstructures Of ?TiC+Ti₅Si₃? Reinforced Copper Matrix Composites

Because of its good conductivity and ductility,copper is widely used in practical production.However,some shortcomings,such as low hardness and strength,poor wear resistance,easy oxidation,and easy softening and deformation above 500?,limit its application.Composite is one of the effective ways to improve its mechanical properties.TiC and Ti₅Si₃ have high melting point,high hardness,high modulus,low density and good chemical stability.Therefore,adding TiC and Ti₅Si₃ reinforcing phases into the Cu matrix can effectively improve its mechanical properties,such as strength and wear resistance,and the related composites have a very broad application prospect.In this paper,Ti₅Si₃ and?TiC+Ti₅Si₃?composite reinforced Cu matrix composites were prepared by in-situ synthesis method,and their microstructure characteristics were studied.The reaction process and mechanism of different systems were also discussed.Firstly,the morphology and distribution of Ti₅Si₃ in copper were studied.The results show that Ti₅Si₃ can form rod-like structure through eutectic reaction in copper-Ti-Si system.By controlling the content and proportion of Ti and Si,the rod-like Ti₅Si₃ can interlace with each other to form bird-nest-like structure skeleton,thus playing a better role in strengthening.Furthermore,a copper matrix composite reinforced by granular TiC and rod Ti₅Si₃ was prepared by adding Ti,Si and graphite powders into the copper melt using graphite powders as raw materials.The synthesized granular TiC was uniformly distributed in the framework formed by Ti₅Si₃.The analysis shows that when Ti powder,Si powder and graphite powder are mixed into the copper melt,the reaction wetting was realized by the reaction of Ti,Si and graphite,As a result,graphite was introduced into the copper melt.The addition of Si made TiC formed by the reaction of Ti and graphite better dispersed into the copper melt.At the same time,the feasibility of preparing?TiC+Ti₅Si₃?composite reinforced copper matrix composites by adding Ti and SiC into the copper melt as carbon source was studied.It was found that?TiC+Ti₅Si₃?composite reinforced copper matrix composites could be prepared from SiC,and the size and distribution of TiC in the composites were more uniform.Similar to adding Ti powder,Si powder and graphite powder into copper melt,Ti powder reacts with SiC to form TiC,and SiC is effectively introduced into copper melt by reaction wetting.In addition,Ti and SiC may react to form SiC-derived carbon.