Coating procedure
A schematic illustration of the fabrication of MMC coating by SHS is shown in
Fig. 1. Double layers of reactant powders were placed on the steel substrate. The
lower layer consisted of 5 g type-I powder, and the upper layer consisted of 50 g type-
II powder. The powder compacts were surrounded by a sand mold. Some igniting
agent, which can be ignited by match, was placed on the top of the type-II powder
compact to trigger the aluminothermic reactions. The reactions happened quickly
and lasted for only several seconds. Finally, a coating with a thickness of
∼3 mm was
produced on the steel substrate.