High-elongation-percentage silver-based electric contact material and preparation method thereof

The invention relates to a metal matrix composite material technology and aims at providing a high-elongation-percentage silver-based electric contact material and a preparation method thereof. The raw material formula is composed of, by weight percent, 84%-88% of silver powder, 1%-8% of silicon carbide whiskers, 2%-6% of copper fibers, 1%-12.9% of nanometer silica sol and 0.1%-1% of a surface modification agent. By means of modification of the nanometer silica sol, a continuous network structure is formed in a silver matrix, good properties of the silicon carbide whiskers and the copper fibers are brought into full play, the elongation percentage, the conductivity and the tensile strength of the silver-based electric contact material are improved, and therefore the defects that an existing environment-friendly silver-based electric contact material is poor in machinable property, high in electrical resistivity and the like can be overcome. The silver-based electric contact material is environment-friendly in