Abstract: Method for coating boron particles with a thin ceramic layer. The method provides for thermal decomposition of a hydrocarbon gas in the presence of the boron particles. The coated particles are useful in fuels, giving improved combustion in solid propellant and ramjet fuels.

Abstract: A solid composition capable of self-sustained combustion to produce gaseous nitrogen and nonvolatile solids as its combustion products comprises a mixture of a first metal azide and the oxide or salt of a second metal which second metal is below the first metal in the electrochemical series and which is capable of being substituted by the first metal in the oxide or salt. Many combinations of various components may be used, but some care is required to select only those combinations in which the solid products are nonvolatile at the temperatures encountered during the combustion. A representative system employes iron oxide and sodium azide according to the following reactions:Fe.sub.2 O.sub.3 +6NaN.sub.3 .fwdarw.2Fe+3Na.sub.2 O+9N.sub.2 .uparw.Another embodiment of the invention generates mixtures of nitrogen and other gases such as carbon dioxide, carbon monoxide and/or water particularly suitable for use in lasers.