PHYSICAL PROPERTIES OF SHORT CARBON FIBRE REINFORCED SILVER COMPOSITES

The electric contact is always made of silver and graphite, the electric conductivity of contact materials decreases as the graphite content increased. The hardness of silver-graphite is low, for example, the hardness of the 3wt% graphite-silver is HB 24.5-39.8MPa, and the electric conductivity is 72% IACS. The present work reports the similarity of electric conductivity for the 3wt% short carbon fibre-Ag composite and 3wt% graphite-silver. However, the hardness of the short carbon fiber-Ag composite is two times harder than that of graphite-silver. The specific gravity of graphite is 2.2 g/cm3, and that of carbon fibre is 1.75 g/cm3, so the 3wt% short carbon fibre-Ag composite contact will still save 5-7%Ag. The electric life of Ag-carbon fibre is much higher than silver-graphite at the same Ag contact.