20100290845 | CARBIDE ROTARY TOOL - A cutting edge portion intermediate form that is a pre-sintered body of the cutting edge portion and a supporting portion intermediate form that is a fully sintered body of the supporting portion are manufactured separately. Full sintering is then performed where front end portion of the supporting portion intermediate form is inserted into an insertion hole of the cutting edge portion intermediate form. During sintering, cobalt particles in powdered materials are converted into a liquid phase, and contracting occurs. Because the supporting portion intermediate form has already been fully sintered, only the cutting edge portion intermediate form contracts. The front end portion of the supporting portion intermediate form is squeezed by the cutting edge portion intermediate form. The carbide tip is therefore created in which the cutting edge portion and the supporting portion are strongly bonded. | 11-18-2010 |