Abstract: This invention is for an inexpensive flexible heater material (heat pad) for food heating, medical compresses and the like. The heat pad is a composite material consisting of a supercorroding metallic alloy powder dispersed throughout a porous polyethylene matrix. The supercorroding alloy material consists of a powdered alloy of magnesium and iron which is produced by high energy powder metallurgical milling techniques. Pressureless sintering of a mixture of the supercorroding alloy powders with UHMW polyethylene powder results in the formation of a flexible porous matrix material with active ingredients therein that are readily activated with a suitable electrolyte fluid.