LIBRARY OF CONGRESS WASHINGTON D C AEROSPACE TECHNOLOGY DIV
Pagination or Media Count:
Two methods are described for improving machinability and metal removal rates in the machining of hardened steel, chilled cast iron, and other metals and alloys which are difficult to machine. The methods include resistance heating by an electric current passing from the cutting tool through the workpiece, or entering directly into the workpiece from a special terminal. The second method was favored since the cutting-tool life was increased by 30 to 50. Sintered WC containing 2 to 3 Co and ceramic cutting tools were used. The combined action of the electric current and heat generated during cutting heated a thin layer of metal to 950 to 1100 C. This facilitated cutting, reduced friction and the cutting force required as well as eliminating chatter.