A protective coat formed by thermal spraying, and having an outstanding durability against corrosion by a molten light alloy. A thermal spraying composite material used to form such a coat contains from about 30 to about 70% by weight of molybdenum boride, from about 20 to about 40% by weight of nickel or cobalt, from about 5 to about 20% by weight of chromium, and from about 5 to about 10% by weight of at least one metal boride selected from the borides of Cr, W, Zr, Ni and Nb.
展开▼