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AssigneesNanodyne Incorporated, Rutgers University
InventorsLarry E. McCandlish, Rajendra K. Sadangi
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A low melting point alloy is used to sinter metal carbide particles. The alloy is a eutectic-like alloy formed from a binding metal such as iron, cobalt or nickel, in combination with vanadium and chromium. The alloy is preferably formed by forming two separate alloys and blending these together. The first alloy is formed by spray drying together a solution of a binding metal salt such as a cobalt salt with a solution of a chromium salt. The formed particles are then carburized to form a cobalt-chromium-carbon alloy. A separate vanadium alloy is formed in the same manner. The two are combined to establish the amount of chromium and vanadium desired, and this, in turn, is used to sinter metal carbide parts. This permits sintering of the metal carbide parts at temperatures less than 1250.degree. C. and in turn significantly inhibits grain grown without a significant decrease in toughness. It is particularly adapted to form carbide products wherein the carbide grain size is as low as 120 nanometers.
A low melting point alloy comprising at least one binding metal selected from the group consisting of iron, cobalt and nickel and at least one of a grain growth inhibiting metal selected from the group consisting of vanadium, chromium, tantalum and niobium in an amount effective to provide an alloy having a liquid formation temperature of less than about 1300.degree. C. and carbon in an amount effective to form carbides of said grain growth inhibiting metal wherein said alloy has no more than 60% iron.
An article, comprising particles of a ceramic powder that have been sintered with a sintering aid comprising a low melting alloy comprising at least one binding metal selected from the group consisting of iron, cobalt and nickel and at least 3% of a grain growth inhibiting metal selected from the group vanadium, chromium, tantalum and niobium in an amount effective to provide an alloy having a liquid formation temperature of less than about 1300.degree. C. and carbon in an amount effective to form carbides of said grain growth inhibiting metal, wherein said alloy has no more than 60% iron.
An article comprising particles of a cermet powder that have been sintered by use of a sintering aid comprising a low melting alloy comprising at least one binding metal selected from the group consisting of iron, cobalt and nickel and at least one grain growth inhibiting metal selected from the group consisting of vanadium, chromium, tantalum and niobium in an amount effective to provide an alloy having a liquid forming temperature of less than about 1300.degree. C. and carbon in an amount effective to form carbides of said grain growth inhibiting metal, wherein said alloy has not more than 60% iron.
An article, comprising particles of a ceramic powder and particles of a cermet powder that have been sintered by use of a sintering aid comprising a low melting alloy comprising at least one binding metal selected from the group consisting of iron, cobalt and nickel and at least one grain growth inhibiting metal selected from the group vanadium, chromium, tantalum and niobium in an amount effect to provide an alloy having a liquid formation temperature of less than about 1300.degree. C. and carbon in an amount effective to form carbides of said grain growth inhibiting metal, wherein said alloy has no more than 60% iron.
Dependencies are inferred from the claim text.