form a compound coating for example if the atoms comprise titanium and the gas comprises nitrogen the coating can comprise titanium nitride the work piece 8 to be coated is preferably an aircraft part such as an airfoil however if desired the work piece can be any desired structure such as drill bits routers saw blades or any other tool the work piece 8 can be formed of any desired material such as steel nickel and titanium and alloys thereof examples of suitable cathodic materials include titanium aluminum chromium and mixtures thereof titanium and aluminum are preferred particularly preferred cathodic materials that can be deposited as metals and or in reactive gas to form nitrides carbides oxides or mixtures thereof are chromium aluminum titanium and other group iv v and vi transition metals from the periodic table as well as the lanthanide series of metals such as but not limited to lanthanum cerium neodymium and gadolinium examples of suitable gases include nitrogen and argon and mixtures thereof while nitrogen and argon are preferred other gases such as hydrocarbons for example acetylene or oxygen and any other gas can be used to provide desired properties to the macroparticles and or coating the process is conducted so that at least one of the streams contains macroparticles comprising.