SBIR-STTR Award

Under this STTR, Imaging Systems Technology (IST) in cooperation with Georgia Institute Technology (GIT) will develop and mature models to predict mechanical properties of refractory alloys with an eye toward tailoring these alloys for specific applications. In particular, this research will focus on addressing core aspects of Integrated Computational Materials Engineering (ICME) as it applies to novel Molybdenum-Silicon-Boron Composites (Mo-Si-B) and its associated processing method. Specifically the research will focus on Molybdenum-Silicon-Boron Composites (Mo-Si-B) fabricated through a novel powder processing based on the Georgia Tech Reaction Sintered (GTRS). Model development will focus on Mo-Si-B composite systems fabricated using ultrasonic spray drying of the constituent components.

Benefit:
Mo-Si-B is being investigated as a potential replacement for superalloys. Successful development of Mo-Si-B will result in significant opportunity to: use U.S.-sourced material, improve technical performance of many high-temperature systems, reduce cost, and minimize environmental impact. The successful development of Mo-Si-B promises advantages over superalloys. Mo-Si-B exhibits significantly better oxidation resistance at high temperatures. This makes it useful for many high temperature applications including heat exchangers, furnace elements, and ultimately gas turbine engines. It is estimated that Mo-Si-B used in turbines will allow jets to improve fuel efficiency by 30% via increased hot section temperatures. From a military perspective, increased fuel savings and higher performance engines will allow the U.S. to maintain superiority over adversaries. From a dual use perspective, increased fuel efficiency in commercial aircraft will result in a reduced operating costs and a decrease in the carbon footprint. Thus, Mo-Si-B is also green 0x9D technology. Another important military advantage is that the base materials, molybdenum, silicon, and boron are sourced from U.S. mines. Thus a stable supply of Mo-Si-B is available regardless of international political circumstances.

Keywords:
Superalloy, Superalloy, ICME, Mo-Si-B, Boron, silcon, Molybdenum, MoSiB, Integrated Computational Materials Engineering, Mo-3Si-B

The objective of the work described in this proposal is to aid in the advancement of Mo-Si-B alloys for use in high temperature applications such as hot gas stream components in turbine engines. Such alloys are being characterized for their monotonic tensile properties in tension and compression as well for their creep resistance. Likewise, multiphase Mo-Si-B alloys have been studied in terms of monotonic and cyclic crack growth and creep fatigue interactions. Less is known about their cyclic deformation response. Computer modeling has been applied to the Mo-Si-B alloy system. However, only 2D studies have been conducted on this material. The accuracy of prediction was found to be very good when the 2D microstructure based simulations were conducted. These studies can be extended to model the failure mechanisms with high level of accuracy because of capturing the stress profile in the material with very high level of accuracy, including the stress concentration location and magnitude and crack length for intergranular fracture. The present work will strive to develop 3D models of the alloy microstructure, and conduct analysis over a range of temperatures and strain rate; all of which are not yet available for this alloy in the existing studies.

Benefit:
Components constructed of Mo-Si-B alloys operating in air at 1300C without cooling would greatly advance turbine technology. This advancement would cut fuel cost and or increase performance of both military and commercial aircraft. In regard to military operation, this material promises higher speed and stronger lift capabilities. In regard to commercial airlines, this material cut fuel cost by 20-40% with a savings approaching the realm of $500 Billion/yr.

Keywords:
refractory metal, Intermetallic, characterization, Mo-Si-B, Oxidation Resistant Alloys, High Temperature, ICME, Molybdenum Alloys