Study On The Composing And Properties Of The Silver Matrix Composites

In the paper,the three kinds of the silver matrix composites that are Ag/Cu/G/CF composites ,Ag/Cu/AlN/G composites and Ag/Cu/MoS2(G)/CF composites were prepared by the traditional powder metallurgic process. The differents proportion of ingredient of the composites were designed.The density, hardness, electrical resisti vity, bend strength and mechanical wear property were tested.The microscopic stru cture and micromechanism of composites were analyzed through metallographical, XRD,SEM,AFM and the best proportion of ingredient of the composites was found.Ag/Cu/G/CF composite is a common electrical brush material.Through researchi ng the different contents G and Cu of composites,the results show that the structur e are more homogeneous and G is the phase of dispersion distributing in the matrix when the G content is less than 9wt%.Cu has good electrical conductivity and strength en the matrix.XRD shows that there isn't obvious solid solution between Ag and Cu.Cu leads to a little rise of the electrical resistivity and can replace Ag partly.The content of Cu cann't exceed 7wt%.The result of researching mechanical wear property indicate that G has the function of reducing the wear.The wear extent is minimum when the content of G and Cu is 9wt% and 7wt% respectively.Considering the good wear-resisting property and the low coefficient of thermal expansion,the Ag/Cu/AlN/G composites were prepared.The hardness and the electri cal resistivity rise,the bend strength descends with the increasing of AlN content.U nder 0.5wt% AlN the composite has a high hardness and good plasticity.,while the electrical resistivity only descends little.When the content of AlN is 0.5wt%,the wear extent isn't more than 0.04mm.Under the condition of 4N load the wear extent isn't more than 0.06mm.The wear property is good.The results of the study on Ag/Cu/MoS2(G)/CF composites indicate that density,bend strength and hardness rise and electrical resistivity falls with the M0S2 increasing.The results of researching the structure show that the structure is homogeneous and it benefit to enhance the comprehensive properties of the composites when the content of M0S2 is less than 5wt%.