Abstract:
PROBLEM TO BE SOLVED: To provide a method for manufacturing a submicron cemented carbide cutting tool insert consisting of tungsten carbide and cobalt by the conventional process comprising a stage of subjecting a powder mixture of WC, Co, and a conventional grain growth inhibitor to wet-kneading to form a slurry, a stage of drying the slurry into powder, a stage of subjecting the powder to uniaxial pressing in a pressing tool to form an article of desired shape, and finally a stage of sintering. SOLUTION: At the time of the sintering stage, a cemented carbide insert of this kind tends to shrink usually in a direction parallel to the pressing direction rather than in a direction perpendicular to the pressing direction. As the result, the pressing requires a special tool or requires, after sintering of the insert, long-time grinding which causes a raise in manufacturing costs. In this method, with respect to a cemented carbide of 7.5 to 25 wt.% Co content, such defect can be removed by using a WC powder having an FSSS grain size dWC of less than 1 μm and a Co powder having an FSSS grain size dCo satisfying the condition that the value of dWC/dCo becomes 0.75-1.5.
Abstract:
PROBLEM TO BE SOLVED: To provide a hard material based on submicron WC in a bonding phase having hardenability. SOLUTION: In cemented carbide in which a bonding phase having hardenability is incorporated with 50 to 90 mass % submicron WC, the bonding phase is composed of Fe, 10 to 60 mass % Co,
Abstract:
PROBLEM TO BE SOLVED: To provide a fine grained cutting tool insert consisting of a cemented carbide substrate and a coating. SOLUTION: The cemented carbide substrate comprises WC, binder phase, and vanadium containing cubic carbide phase with a binder phase enriched surface zone essentially free of cubic carbide phase. The cemented carbide substrate is fine grained cemented carbide consisting of a first phase based on tungsten carbide WC, having an average grain size less than 1.5 μm, preferably less than 1.0 μm and most preferably less than 0.6 μm, a metallic binder phase based on Co and/or Ni and finally at least one additional phase comprising at least one carbonitride or mixed carbonitride containing vanadium. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
A method for manufacturing a cemented carbide body (1), comprising the following steps: - forming a first part (2, 9, 14, 17) of a first powder composition comprising a first carbide and a first binder phase, - sintering the first part (2) to full density in a first sintering operation, - forming a second part (3) of a second powder composition comprising a second carbide and a second binder phase, - sintering the second part (3) to full density in a second sintering operation, - bringing a first surface (4) of the first part (2) and a second surface (5) of the second part (3) in contact, and - joining the first and second surface in a heat treatment operation.