Kennametal Inc.

Debangshu Banerjee

Xin Deng

Qingjun Zheng

Terry Wayne Kirk

Hongbo Tian

Rodrigo Alejandro Cooper

Shivanand I Majagi

Michael Wilfert

In one aspect, articles are described comprising wear resistant coatings employing composite architectures including refractory layers of varying compositions and phases. Briefly, a coated article comprises a substrate and a coating deposited by chemical vapor deposition (CVD) adhered to the substrate, the coating comprising an inner refractory layer comprising MAlN wherein x&#x2265;0.7 and M is titanium, chromium or zirconium and an outer zirconia layer or outer multiphase refractory layer comprising an alumina phase and an oxide phase comprising at least one Group IVB metal, wherein the MAlN has less than 15 weight percent hexagonal phase.

CVD composite refractory coatings and applications thereof

Carbide pellets including relatively small amounts of metallic binder are produced by steps of pressing, comminuting, shaping and sintering. The carbide pellets may be used as wear resistant hard facing materials that are applied to various types of tools. The carbide pellets provide improved mechanical properties such as hardness and abrasiveness while maintaining required levels of toughness and strength.

Carbide pellets for wear resistant applications

The present invention includes a matrix powder system comprising one or more polycrystalline carbides, binderless carbides, or a combination thereof, a composite comprising the matrix powder system and a metal bond phase, a matrix bit body for a drill bit for oil and gas drilling made of this composite material, and a drill bit for oil and gas drilling comprising the matrix bit body and at least one cutter. The polycrystalline and/or binderless carbides may comprise carbides of W, Ti, V, Cr, Nb, Mo, Ta, Hf, Zr, or a combination thereof. The binderless carbides have less than 3 wt. % binder and the binderless and/or polycrystalline carbides may have a grain size of &#x2266;15 &#x3bc;m and a hardness of &#x2267;1900 HV (0.5 kgf). Additional ceramic components and/or metals may also be present in the matrix powder system. Alternatively, the composite material may be present on only a portion of the matrix bit body surface.

Matrix powder system and composite materials and articles made therefrom

A hard alloy material comprising tungsten carbide in an amount of less than 50 weight percent of the material, titanium carbide in an amount of at least about 30 weight percent, and a binder material of cobalt and nickel. In other aspects of the invention, molybdenum and/or chromium are included to further lower the thermal conductivity of the material. The thermal conductivity of the material of the invention is about 12 Watt/m&#xb0; K. or less.

Cemented carbide with ultra-low thermal conductivity

A product having a chromium carbide based cemented carbide composition with a nickel and/or chromium based binder is disclosed. It possesses excellent corrosion resistance in combination with good strength and hardness/abrasion resistance. The average chromium carbide grain size is less than 10 &mgr;m.

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Springdale, AR, United States of America

Debangshu Banerjee