Kennametal Inc.

John S Van Kirk

Ted Richard Massa

Edward V Conley

Robert R McNaughton, Jr

Methods for making, methods for using and articles comprising cermets, preferably cemented carbides and more preferably tungsten carbide, having at least two regions exhibiting at least one property that differs are discussed. Preferably, the cermets further exhibit uniform or controlled wear to impart a self-sharpening character to an article. The multiple-region cermets are particularly useful in wear applications. The cermets are manufactured by juxtaposing and densifying at least two powder blends having different properties (e.g., differential carbide grain size or differential carbide chemistry or differential binder content or differential binder chemistry or any combination of the preceding). Preferably, a first region of the cermet comprises a first ceramic component having a relatively coarse grain size and a prescribed binder content and a second region, juxtaposing or adjoining the first region, comprises a second ceramic component, preferably carbide(s), having a grain size less than the grain size of the first region, a second binder content greater than the binder content of the first region or both. These articles have an extended useful life in such applications as, for example, wear. The multiple region cermets of the present invention may be used with articles comprising tools for materials manipulation or removal including, for example, mining, construction, agricultural, and metal removal applications.

Method of using composite cermet articles

Methods for making, methods for using and articles including cermets, preferably cemented carbides and more preferably tungsten carbide, having at least two regions exhibiting at least one property that differs are discussed. Preferably, the cermets further exhibit a portion that is binder rich and which gradually or smoothly transitions to at least a second region. The multiple-region cermets are particularly useful in compressively loaded application wherein a tensile stress or fatigue limit might otherwise be excessive for monolithic articles. The cermets are manufactured by juxtaposing and densifying at least two powder blends having different properties (e.g., differential carbide grain size, differential carbide chemistry, differential binder content, differential binder chemistry, or any combination of the preceding). Preferably, a first region of the cermet includes a first ceramic component and a prescribed binder content and a second region, juxtaposing or adjoining the first region, of the cermet includes a second ceramic component and a second binder content less than the prescribed binder content. The multiple region cermets of the present invention may be used in materials processing technology including, for example, compression technology, extrusion, supercritical processing, chemical processing, materials processing, and ultrahigh pressure.

Method of molding green bodies

Methods for making, methods for using and articles comprising cermets, preferably cemented carbides and more preferably tungsten carbide, having at least two regions exhibiting at least one property that differs are discussed. Preferably, the cermets further exhibit a portion that is binder rich and which gradually or smoothly transitions to at least a second region. The multiple-region cermets are particularly useful in compressively loaded application wherein a tensile stress or fatigue limit might otherwise be excessive for monolithic articles. The cermets are manufactured by juxtaposing and densifying at least two powder blends having different properties (e.g., differential carbide grain size, differential carbide chemistry, differential binder content, differential binder chemistry, or any combination of the preceding). Preferably, a first region of the cermet comprises a first ceramic component and a prescribed binder content and a second region, juxtaposing or adjoining the first region, of the cermet comprises a second ceramic component and a second binder content less than the prescribed binder content. The multiple region cermets of the present invention may be used in materials processing technology including, for example, compression technology, extrusion, supercritical processing, chemical processing, materials processing, and ultrahigh pressure.

Composite cermet articles and method of making

Methods for making, methods for using and articles comprising cermets, preferably cemented carbides and more preferably tungsten carbide, having at least two regions exhibiting at least one property that differs are discussed. Preferably, the cermets further exhibit uniform or controlled wear to impart a self-sharpening character to an article. The multiple-region cermets are particularly useful in wear applications. The cermets are manufactured by juxtaposing and densifying at least two powder blends having different properties (e.g., differential carbide grain size or differential carbide chemistry or differential binder content or differential binder chemistry or any combination of the preceding). Preferably, a first region of the cermet comprises a first ceramic component having a relatively coarse grain size and a prescribed binder content and a second region, juxtaposing or adjoining the first region, comprises a second ceramic component, preferably carbide(s), having a grain size less than the grain size of the first region, a second binder content greater than the binder content of the first region or both. These articles have an extended useful life relative to the useful life of monolithic cermets in such applications as, for example, wear. The multiple region cermets of the present invention may be used with articles comprising tools for materials manipulation or removal including, for example, mining, construction, agricultural, and metal removal applications.

Methods for making, methods for using and articles having cermets, preferably cemented carbides and more preferably tungsten carbide, having at least two regions exhibiting at least one property that differs are discussed. Preferably, the cermets further exhibit a portion that is binder rich and which gradually or smoothly transitions to at least a second region. The multiple-region cermets are particularly useful in compressively loaded application wherein a tensile stress or fatigue limit might otherwise be excessive for monolithic articles. The cermets are manufactured by juxtaposing and densifying at least two powder blends having different properties (e.g., differential carbide grain size, differential carbide chemistry, differential binder content, differential binder chemistry, or any combination of the preceding). Preferably, a first region of the cermet has a first ceramic component and a prescribed binder content and a second region, juxtaposing or adjoining the first region, of the cermet has a second ceramic component and a second binder content less than the prescribed binder content. The multiple region cermets of the present invention may be used in materials processing technology including, for example, compression technology, extrusion, supercritical processing, chemical processing, materials processing, and ultrahigh pressure.

Method of making composite cermet articles

Methods for making, methods for using and articles comprising cermets, preferably cemented carbides and more preferably tungsten carbide, having at least two regions exhibiting at least one property that differs are discussed. Preferably, the cermets further exhibit uniform or controlled wear to impart a self-sharpening character to an article. The multiple-region cermets are particularly useful in wear applications. The cermets are manufactured by juxtaposing and densifying at least two powder blends having different properties (e.g., differential carbide grain size or differential carbide chemistry or differential binder content or differential binder chemistry or any combination of the preceding). Preferably, a first region of the cermet comprises a first ceramic component having a relatively coarse grain size and a prescribed binder content and a second region, juxtaposing or adjoining the first region, comprises a second ceramic component, preferably carbide(s), having a grain size less than the grain size of the first region, a second binder content greater than the binder content of the first region or both.

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Murrysville, PA, United States of America

John S Van Kirk