SBIR-STTR Award

Many structural applications use components fabricated from titanium or aluminum because conventional magnesium alloys have insufficient strength and poor corrosion properties. These magnesium alloys rely on precipitation strengthening. At elevated temperatures, the precipitates coarsen, reducing the strength of the alloy. However, the elevated temperature strength of magnesium is retained when thermally stable particles are used to strengthen the alloy. These particles also increase the stiffness of the alloy to levels comparable to aluminum and titanium alloys. Furthermore, removal of transition metals from the alloys increases their corrosion resistance. Ultra-fine particles are being incorporated into pure magnesium by pressure infiltration to form oxide dispersion-strengthened (ODS) magnesium. These alloys derive strength from the fine particles and resulting dislocation substructures. By using particles which are thermally stable, the alloys retain their strength at temperature for long periods of time. Hot hardness tests conducted on the alloys are being used to measure Strength at temperature. Larger dispersion-strengthened samples are being fabricated. These samples are being used to more completely characterize the mechanical behavior, fracture properties, corrosion resistance, and physical properties of the alloys as cast and after wrought processing.The potential commercial application as described by the awardee: Successful completion of the research will determine the feasibility of employing pressure infiltration to produce ODS magnesium with elevated temperature capability and improved modulus. Pressure infiltration is a low-cost process and is expected to produce costeffective ODS magnesium alloys.

In phase II, the fundamental microstructure/processing/property relationships for ODS magnesium alloys will be investigated. Larger samples will be produced while key process parameters are systematically varied. These samples will be investigated microstructurally by optical and SEM techniques. Standard elevated temperature tensile and creep testing will be performed in condition, the most promising samples will be further processed by hot working techniques and the same type of microstructural, mechanical, and physical property evaluations. Successful completion of the Phase II research will provide the foundation for future commercialization of ODS magnesium with elevated temperature capability and improved modules produced by pressure infiltration. Pressure infiltration is a low cost process and is expected to produce cost-effective ODS magnesium alloys. Such alloys could lead to the development of more fuel efficient and environmentally cleaner automobiles.