Research On Preparation,Microstructures And Properties Of TiC/Diamond Reinforced Cu Matrix Composites

Copper is widely used in electronics,electrical,automotive and machinery manufacturing because of its excellent electrical conductivity,thermal conductivity and corrosion resistance.However,the low hardness and poor wear resistance of pure copper limit its application.The mechanical properties and wear resistance of copper can be effectively improved by adding one or more kinds of ceramic particles or carbon materials into Cu matrix to prepare composites.In this paper,Ti C reinforced Cu matrix composite and diamond reinforced Cu matrix composite were prepared by melting reaction method with carbon black and diamond as carbon sources respectively,and the preparation mechanism was studied.At the same time,the composite microstructures were analyzed,and the properties such as hardness,conductivity and wear resistance were tested.It is found that carbon black can be introduced into Cu melt by Ti-C reactive wetting and Ti C can be synthesized.However,due to the original aggregation state of carbon black and poor wettability of Ti C and Cu melt,Ti C particles are easy to agglomerate.The ratio of Ti/C in the raw material is changed to produce Ti C_x with more carbon vacancies.The wettability of Ti C is improved due to the the low carbon content Ti C_x formation and excess titanium in the melt,so that the Ti C particles are more uniformly distributed in Cu matrix.When diamond(D)is used as carbon source,it is difficult to introduce diamond into Cu melt based on Ti-D system.When Si is added into Ti-D system to form Ti-Si-D system,it is found that it can introduce diamond into Cu melt by reaction wetting.It is believed that after the introduction of Si into Ti-D system,Ti₅Si₃ will form earlier than Ti C,and then prevent it connecting into network structure during the growth of Ti C shell,which promotes the dispersion of D@Ti C in melt.It is also found that the original diamond particle size and its aggregation state affect the distribution state of D@Ti C particles in Cu matrix.The smaller the diamond particle size is,the easier it is to aggregate,and the D@Ti C particles generated are also easy to aggregate in Cu matrix.When the diamond particle size is 4-7?m,the structure distribution of the Cu matrix composite is the most uniform.Performance tests show that the diamond reinforced Cu matrix composite has high hardness and good wear resistance.Among the Cu-2Ti-1Si-1D,Cu-2Ti-1Si-2D and Cu-2Ti-1Si-3D composites prepared with4-7?m diamond,the Cu-2Ti-1Si-2D composite has the advantages of small friction coefficient,less mass loss and excellent wear resistance.