Abstract: A method is disclosed for controlling a self-propagating reaction in a particulate medium. The method comprises controlling the boundary heat flux of the reaction to produce reaction waves which travel through the particulate medium undergoing a self-propagating reaction. The method provides a product having a unitary, solid structure with layers of alternating density. Preferably the reaction is a reaction between two metals to produce an intermetallic compound or between a metal and a non-metal to produce a ceramic compound. Nickel aluminide is a preferred intermetallic compound. Also disclosed is a controlled reactive sintering process for producing a finely divided intermetallic compound comprising comminuting the layered body of intermetallic compound.

Abstract: An apparatus for continuously winding a length of material into a helical form includes a frame structure and a plurality of rollers mounted on the frame structure. Each roller has a non-grooved surface with portions of a different diameter, a longitudinal axis and oppositely positioned first and second ends, and the plurality of rollers are arranged about a winder axis in a substantially circular fashion. The rollers are individually rotatably driven and the first and second ends of each roller are offset with respect to one another as viewed from one end of the respective roller along a line parallel to the winder axis and passing through the longitudinal axis of the respective roller at the one end of the respective roller. The method includes continuously feeding a length material onto a plurality of rollers that are arranged in a substantially cylindrical manner about a winder axis so that the outer surfaces of the rollers define a cylindrical winder surface about which the material is to be wound.