ULTRA-FINE CEMENTED CARBIDE Ni BINDER PHASE AND TOOL USING THE SAME

Abstract

Provided is a high hardness ultra-fine cemented carbide with a Ni binder phase for a wear resistant tool. An ultra-fine cemented carbide having high specularity and/or high strength, high hardness, and high wear resistance is obtained by using an ultra-fine raw powder of WC, controlling the amount of Ni, and the contents of V and Cr, so that a third phase containing V and Cr precipitates in a microstructure of the cemented carbide in a finely dispersed state, and at the same time, the size of Ni pool is controlled to a value equal to or less than the average grain size of WC. By using this cemented carbide, the range of application to an aspherical glass lens mold, an ultrahigh pressure generation container for neutron diffraction experiment, a non-ferromagnetic corrosion resistant and wear resistant tool, and the like is expanded.

1 . A tungsten carbide (WC) based ultra-fine cemented carbide suitable for a wear resistant tool, the cemented carbide being based on WC and Ni, and also containing V and Cr, the Ni being contained in an amount of 0.12 to 9 mass %, the V being contained in an amount of 5 to 100 mass % with respect to the amount of the Ni, and the Cr being contained in an amount of 11 to 300 mass % with respect to the amount of the Ni, so that, in addition to a WC phase and a Ni binder phase, a third phase containing the V and the Cr is dispersed in a microstructure of the cemented carbide with a maximum size of 0.3 μm or less, and the cemented carbide has a hardness of 2100 to 2800 HV10 and a maximum size of a Ni pool, or aggregated portion of Ni of the binder phase, of 0.3 μm or less, and has an average grain size of the WC of 0.3 μm or less, WC powder used to make the cemented carbide being obtained by intensively pulverizing the WC and Ni powder used to make the cemented carbide being obtained by intensively pulverizing Ni so that the Ni powder is work-hardened. 
     
     
         2 . An aspherical glass lens mold produced from a tungsten carbide (WC) based ultra-fine cemented carbide suitable for a wear resistant tool, the cemented carbide being based on WC and Ni, and also containing V and Cr, the Ni being contained in an amount of 0.12 mass % to 0.3 mass %, the V being contained in an amount of 30 to 100 mass % with respect to the amount of the Ni, and the Cr being contained in an amount of 130 to 300 mass % with respect to the amount of the Ni, so that, in addition to a WC phase and a binder phase, a third phase containing the V and the Cr is dispersed in a microstructure of the cemented carbide with a maximum size of 0.3 μm or less, and the cemented carbide has a hardness of 2450 to 2800 HV10 and a maximum size of a Ni pool, or aggregated portion of Ni of the binder phase, of 0.3 μm or less, and has an average grain size of the WC of 0.3 μm or less, WC powder used to make the cemented carbide being obtained by intensively pulverizing the WC and Ni powder used to make the cemented carbide being obtained by intensively pulverizing Ni so that the Ni powder is work-hardened. 
     
     
         3 . An ultrahigh pressure generation container for neutron diffraction experiment produced from a tungsten carbide (WC) based ultra-fine cemented carbide suitable for a wear resistant tool, the cemented carbide being based on WC and Ni, and also containing V and Cr, the Ni being contained in an amount of 3 to 9 mass %, the V being contained in an amount of 5 to 15 mass % with respect to the amount of the Ni, and the Cr being contained in an amount of 11 to 50 mass % with respect to the amount of the Ni, so that, in addition to a WC phase and a Ni binder phase, a third phase containing the V and the Cr is dispersed in a microstructure of the cemented carbide with a maximum size of 0.3 μm or less, and the cemented carbide has a hardness of 2100 HV10 to 2700 HV10 and a maximum size of a Ni pool, or aggregated portion of Ni of the binder phase, of 0.3 μm or less, and has an average grain size of the WC of 0.3 μm or less, WC powder used to make the cemented carbide being obtained by intensively pulverizing the WC and Ni powder used to make the cemented carbide being obtained by intensively pulverizing Ni so that the Ni powder is work-hardened. 
     
     
         4 . A non-ferromagnetic corrosion resistant and wear resistant tool produced from a tungsten carbide (WC) based ultra-fine cemented carbide suitable for a wear resistant tool, the cemented carbide being based on WC and Ni, and also containing V and Cr, the Ni being contained in an amount of 3 to 9 mass %, the V being contained in an amount of 5 to 15 mass % with respect to the amount of the Ni, and the Cr being contained in an amount of 11 to 50 mass % with respect to the amount of the Ni, so that, in addition to a WC phase and a binder phase, a third phase containing the V and the Cr is dispersed in a microstructure of the cemented carbide with a maximum size of 0.3 μm or less, and the cemented carbide has a hardness of 2100 to 2700 HV10 and a maximum size of a Ni pool, or aggregated portion of Ni of the binder phase, of 0.3 μm or less, and has an average grain size of the WC of 0.3 μm or less, WC powder used to make the cemented carbide being obtained by intensively pulverizing the WC and Ni powder used to make the cemented carbide being obtained by intensively pulverizing Ni so that the Ni powder is work-hardened.