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US 6,190,762 B1Granted
Composite body and method of producing the same
AssigneeWidia GmbH
InventorsKlaus Rödiger, Klaus Dreyer, Monika Willert-Porada, Thorsten Gerdes
Life of this patent
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Abstract
A cermet or hard metal body is formed from elemental metal, carbon and a nitrogen source such as a metal nitride or an organic nitrogen source by microwave sintering such that chemical reaction occurs with the formation of carbides and/or carbonitrides. The elemental metal, carbon and nitrogen source are mixed together and prepressed to form the green body which is subjected to the microwave radiation in reaction sintering.
Claims29
An oxide free composite body with a binder metal phase and at least one hard phase comprised of:
- a cermet material with a binder metal phase of 3 to 30 mass percent, the balance being at least one carbonitride phase or;
- a hard metal with at least one hard material phase of 65 to 99 mass percent, the balance being a binder metal phase, wherein the metals of the hard material phase or the carbonitride phase, carbon of the hard material phase or the carbonitride phase, and metal nitrides of the carbonitride phase and solid nitrogen compounds as suppliers of carbon or nitrogen of the hard material phase or the carbonitride phase, are originally exclusively each in powder form and mixed together and compacted to a green body which is then, subjected to reaction sintering under a pressure of <5×105 Pa in a microwave field to chemically form the hard phase or the carbonitride phase and in which the hard phase formed forms a liquid phase with the remaining substances which do not participate in the hard phase reaction, the cermet material being in the form of a cermet composite body with at least 70 volume % having a mean grain size <0.4 μm, the hard metal forming a composite body with at least 70% having a mean grain size <0.5 μm.
A method of producing a composite body comprising:
- a cermet material with a binder metal phase of 3 to 30 mass percent, the balance being at least one carbonitride phase or;
- a hard metal with at least one hard material phase of 65 to 99 mass percent, the balance being a binder metal phase, wherein the metals of the hard material phase or the carbonitride phase, carbon of the hard material phase or the carbonitride phase, and metal nitrides of the carbonitride phase and solid nitrogen compounds as suppliers of carbon or nitrogen of the hard material phase or the carbonitride phase, are originally exclusively each in powder form and mixed together and compacted to a green body which is then, subjected to reaction sintering under a pressure of <5×105 Pa in a microwave field to chemically form the hard phase or the carbonitride phase and in which the hard phase formed forms a liquid phase with the remaining substances which do not participate in the hard phase reaction, the cermet material being in the form of a cermet composite body with at least 70 volume % having a mean grain size <0.4 μm, the hard metal forming a composite body with at least 70% having a mean grain size <0.5 μm, the method comprising forming the hard phase or cermet material by the steps of:
- mixing the requisite metals, the carbon metal nitrides and/or solid nitrogen compounds as suppliers for carbon and/or solid nitrogen compounds as suppliers for carbon and nitrogen, exclusively in powder form, preprocessing the resulting powder mixture to a shaped body under a pressure <5×105 Pa, and subjecting said body, at least briefly, to a microwave field of 0.01 to 10 W/cm3 to effect a reaction sintering.
Dependencies are inferred from the claim text.