Metallurgical compositions containing binding agent/lubricant and process for preparing same
AssigneeHoeganaes Corporation
InventorsWilliam Hendrickson, Sydney Luk
Life of this patent
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Abstract
Improved methods for coating particulate materials at low shear conditions and preferably below the melting point of the coating material are provided. In one aspect, metallurgical compositions are provided that contain a metal-based powder bound to an alloying powder or powders by way of a low melting polymer or wax binding agent, which is preferably polyethylene. The binding agent is blended with the metal-based and alloying powders at elevated temperatures preferably below the melting point of the binding agent. The bonded metallurgical composition can be used in compaction processes to manufacture compacted parts that can be sintered to impart strength.
Claims17
A method of preparing a segregation resistant and dust resistant metallurgical powder composition, comprising:
- (a) providing a mixture of metal-based powder and at least one alloying powder;
- (b) blending with said metal-based powder and said at least one alloying powder a binding agent, in the absence of a solvent, to form an initial blend, where the binding agent is a solid, low melting polymer or wax having a softening temperature below 150° C., and wherein the binding agent has an average particle size in at least one direction of 50 microns or less;
- (c) raising the temperature of the initial blend to at least 50° C. but below the melting point of the binding agent to effect bindingbetween the metal-based powder and the at least one alloying powder by the binding agent;
- and
- (d) lowering the temperature of the mixture to ambient temperture to thereby form the metallurgical powder composition,
- wherein the metal-based powder is present in an amount of at least 80 percent by weight, the alloying powder is present in an amount of between about 0.25 and about 4 percent by weight, and the binding agent is present in an amount between about 0.25 and about 2 percent by weight, based on the total weight of the metallurgical powder composition.
Dependencies are inferred from the claim text.