Patent ID: 7638727

Claim:
A method of heat treating an object to provide different material properties at discrete portions of the object with respect to the rest of the object, the method comprising: initiating a heat treating plasma within a cavity by subjecting a gas to electromagnetic radiation having a frequency less than about 333 GHz in the presence of a plurality of passive plasma catalysts that are introduced into the plasma at different locations corresponding to the discrete portions of the object; masking the object by mode-mixing the electromagnetic radiation; applying the plasma to the object to heat the object to a temperature of between approximately 2,000 degrees Fahrenheit and approximately 3,000 degrees Fahrenheit by the plasma; and adjusting the temperature of the discrete portions of the object by adjusting an amount of electromagnetic radiation to the plasma adjacent said discrete portions while adjusting a plasma catalyst component ratio of the plurality of passive plasma catalysts that are introduced into the plasma proximate said discrete portions for a first period of time sufficient to alter at least one material property of said discrete portions of the object.