Method of cryogenic treatment of tungsten carbide containing cobalt

Abstract

A method of cryogenic treatment of tungsten carbide containing cobalt. A first step involves pre-treating tungsten carbide with microwave sintering, thereby changing the properties of the tungsten carbide. A second step involves lowering the temperature of the microwave sintered tungsten carbide gradually to cryogenic levels. A third step involves raising the temperature of the microwave sintered tungsten carbide gradually back to ambient temperatures. The described combination of microwave sintering and cryogenic treatment produces significant improvement in impact resistance, erosion and corrosion resistance and wear rate.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . A method of cryogenic treatment of tungsten carbide containing cobalt, comprising the steps of: 
 pre-treating tungsten carbide containing cobalt with microwave sintering, thereby changing the properties of the tungsten carbide;    lowering the temperature of the microwave sintered tungsten carbide gradually to cryogenic levels; and    raising the temperature of the microwave sintered tungsten carbide gradually back to ambient temperatures.    
     
     
         2 . The method as defined in  claim 1 , in which the microwave sintered tungsten carbide is held at cryogenic levels to permit cryogenic penetration into the microwave sintered tungsten carbide, prior to the raising of the microwave sintered tungsten carbide back to ambient temperatures.