Method for enhancing the oxidation resistance of a molybdenum alloy, and a method of making a molybdenum alloy
AssigneeUnited Technologies Corporation
InventorDouglas M. Berczik
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Abstract
Methods of enhancing oxidation resistance and methods of making molybdenum alloys are provided. In these methods, alloys are prepared by the addition of silicon and boron in amounts defined by the area of a ternary system phase diagram bounded by the points Mo-1.0%Si-0.5%B, Mo-1.0%Si-4.0%B, Mo-4.5%Si-0.5%B, and Mo-4.5%Si-4.0 B. The methods utilize rapid solidification followed by consolidation at below the melting point. The resultant alloys have mechanical properties similar to other high temperature molybdenum alloys while possessing a greatly enhanced resistance to oxidation at high temperature.
Claims13
A method for enhancing the oxidation resistance of a molybdenum alloy comprising the step of adding silicon and boron to a molybdenum composition comprised of more than 50 weight % molybdenum;
- wherein said step of adding comprises:
- adding said silicon and boron to a melt comprising molybdenum followed by rapid solidification;
- and further comprising the step of consolidating the rapidly solidified alloy to form an alloy in which there is a matrix of body centered cubic molybdenum surrounding discrete particles of intermetallic phase;
- and further wherein said silicon and boron are added in amounts such that the molybdenum alloy having enhanced oxidation resistance that results from said step of adding, consists essentially of a composition defined by the area described by the compositional points of the phase diagram for a ternary system:
- metal-1.0%Si-0.5%B, metal-1.0%Si-4.0%B, metal-4.5%Si-0.5%B, and metal-4.5%Si-4.0%B;
- wherein percentages are weight % and wherein said metal consists essentially of molybdenum as the major component.
A method of making a molybdenum alloy comprising the steps of forming a melt of a composition defined by the area described by the compositional points of the phase diagram for a ternary system:
- metal-1.0%Si-0.5%B, metal-1.0%Si-4.0%B, metal-4.5%Si-0.5%B, and metal-4.5%Si-4.0%B;
- wherein percentages are weight % and wherein said metal consists essentially of molybdenum as the major component;
- rapidly solidifying said melt to form a rapidly solidified material;
- and
- consolidating said rapidly solidified material to form an alloy in which there is a matrix of body centered cubic molybdenum surrounding discrete particles of intermetallic phase.
Dependencies are inferred from the claim text.