TECHNOLOGY AREAS: Air Platform, Materials/Processes

OBJECTIVE: Mature Mo-Si-B material production methodology for Aerospace use. In Phase 1 the process of maturation will optimally include the demonstration of medium scale material production, material lots of 1 to 10 pounds, and the assessment of the benefit of extrusion on the mechanical properties of Mo-Si-B alloys.

DESCRIPTION: Maturation of material production methodologies/techniques is needed for Mo-Si-B alloys. Mo-Si-B powder can be manufactured by a handful of production techniques. One of the most promising avenues for producing Mo-Si-B powder with the necessary cleanliness for aerospace and marine applications is the Spray Dried + Reaction technique. However other processing techniques will be considered if they demonstrate low interstitial impurities (O, N, C). The potential for medium scale production of this powder including the accompanying methodologies for handling and reaction of this powder needs to be demonstrated. This would ideally be demonstrated via processes that can be scaled-up to standard production techniques. Characterization of the powder chemistry and interstitials should be document during each stage of the processing. Following development of a specific process to produce medium scale material lots of Mo-Si-B powder, maturation of the parameters required to perform a small scale Mo-Si-B extrusion is also required. Characterization of the extruded material properties should be performed. Ideally this characterization would include measurement of the tensile properties up to 2300 degrees F and potentially 2500 degrees F, as well as the creep resistance of the alloy at 2000 degrees F or higher. This characterization should also include documentation of the static oxidation resistance at three or four key temperatures across a range between 1500F to 2500 degrees F.

PHASE I: Formulate and produce a moderate quantity of a Mo-Si-B alloy by spray-drying. Process the material to a full density low interstitial material via heat treatment in a suitable atmosphere. Extrude samples of the processed powder and measure the tensile properties of the material. Samples should exhibit a ultimate tensile strength of 60 Ksi or more.

PHASE II: Develop a detailed test plan to scale-up the material production and processing approach from the laboratory size in Phase 1 to an industrial scale. Execute a proto-type small scale industrial production of the material and assess the material properties. Conduct material property tests at the level required to provide data for the design of a suitable component for demonstration in an OEM or DoD core engine test. Provide material for manufacture and test of the suitable component.

PHASE III: Transition the material production methodology to a suitable industrial material producer. Commercialize the material for use in DoD and civilian markets.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: If this technology was successfully developed, the material would have utility as high temperature material of construction for civil air transport and as a high temperature forging die material for both commercial and military production equipment.

REFERENCES:
R.L. Fleischer. "High Temperature, High Strength Materials - an Overview, Journal of Metals 37(12) 16-20, 1985.

J.D. Destefani, Advances in Intermetallics, Advanced Materials and Processes, 135 (2) 37-41, 1989

J.H. Schneibel, et al. Assessment of processing routes and strength of a 3-phase molybdenum boron silicide, Scripta Materialia, 38(7) 1169-1176, 1998

KEYWORDS: Molybdenum Alloys, Refractory Metal, Intermetallic, Oxidation Resistant Alloys, Powder, Powder production, Extrusion

Questions may also be submitted through DoD SBIR/STTR SITIS website.