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Iowa State University and Ames Laboratory researchers have developed a series of alloy design and powder or spray processing steps that lead to the low-cost production of oxidation or corrosion resistant metallic alloys.

Lab scale demonstration

Alloys used in applications such as exhaust valves are increasingly subject to demanding operating environments, such as high temperatures and exposure to corrosive gases; these alloys must also be able to resist high cycle fatigue, extreme surface wear, and long-term creep deformation.  Iron (Fe)-based superalloys have been developed through a mechanical alloying process that results in a dispersoid strengthened metallic material.  However, mechanical alloying can add significant costs for making alloys that perform well in high temperature environments because it requires expensive milling equipment and extensive milling time; thus commercial applications may be limited.  The long milling time required can also lead to contamination within the alloy powders.  To overcome these drawbacks, ISU and Ames laboratory researchers have developed a method of making dispersoid strengthened, corrosion/oxidation resistant atomized alloy powder particles for high temperature structural applications.  The method employs gas atomization reaction synthesis (GARS) linked with alloy design and atomizing parameters to result in the low-cost production of corrosion and/or oxidation resistant metallic alloy particles which are strengthened by disperoids that are highly resistant to coarsening and strength degradation at elevated temperatures.  This new molten metal processing technique can thus result in precision parts with superior properties.

• Economical (simplified process reduces costs and eliminates mechanical alloying process)

• Scalable (commercial productions rates are higher than those for mechanical alloying)

• Effective (enables control of batch-to-batch variation and contamination)

Powder Metallury Processing