Ferrophosphorus composition having improved conductivity and passivation resistance

摘要

A ferrophosphorus composition with improved conductivity and passivation resistance is prepared by treating ferrophosphorus particles with an aqueous solution containing a dilute mineral acid and ions of chromium and a metal selected from the group consisting of zinc, strontium, calcium, barium, lead or copper. In a preferred embodiment, the concentration of chromium and zinc ions in the solution is in the range of about 2 grams/liter to about 10 grams/liter, and the treatment time is from about 2 to about 6 minutes. The treated ferrophosphorus particles can be formulated in a suitable resin binder for use as corrosion resistant coatings, weldable coatings, EMI shielding coatings or electrically conductive coatings. The treated ferrophosphorus particles can also be used in powder metallurgy applications.