Titanium and titanium alloy surfaces can be diffusion coated, and portions of the surface protected against such coating by localized powdered masking layer of about 43% titanium, aluminum in an amount equal to the aluminum content of the surface masked, as well as other metals in an amount about one-fifth of their content in the surface masked. Diffusion coating can be speeded by high heat input. Diffusion coating packs can be made with chemically reduced metal content of sludges. Diffusion aliminizing followed by caustic leaching to remove much of the diffused-in aluminum, yields catalytically and pyrophorically active porous surface that also accepts top coatings. Mixtures of aluminum powder with nickel and/or iron powders react when heated to form Raney-like product that can be leached to become pyrophoric, and when held on a metal foil or gauze web will adhere to the web so that leached product can be used as pyrophoric foil for decoying heat-seeking missiles. Such adhesion is improved by addition of small amount of copper.