Richard A. Wood

Effect of composition on the properties of strain-transformable β titanium alloys

A number of metastableβ titanium alloys were examined to determine the effects of composition on strain-transformation behavior and precipitation hardening response. Maximum ductility as solution heat treated was observed in alloys slightly richer in alloy content than the minimum alloy content required to retain an all-β microstructure on quenching. Such materials transformed to a martensitic structure upon straining and, as a result of strain transformation, developed room temperature ductility exceeding that found in unalloyed titanium. Uniform elongation of 35 to 45 pct was observed in a number of compositions of this type containing major additions of Mo, V, Cr, or Mn. Auxiliary alloy additions of Sn, Al, or Zr, or ternary alloying with molybdenum were necessary to preventω embrittlement during quenching in alloys containing V, Cr, or Mn. Alloying with Fe, Cu, Co, or Ni resulted in low ductility as solution heat treated, but it is probable that optimum amounts of these additions were not studied in this investigation. Oxygen above about 1200 ppm also had a detrimental effect on ductility. All alloys studied showed precipitation hardening when heat treated in the 800° to 1100°F range. Tensile strengths of 170 to 190 ksi were readily attainable in most alloy systems. Ductility as precipitation hardened appeared to be higher in alloys containing at least 6 pct Mo or V than in other alloys studied.

Logistics, Costs, and GHG Impacts of Utility Scale Cofiring with 20% Biomass

This report presents the results of an evaluation of utility-scale biomass cofiring in large pulverized coal power plants. The purpose of this evaluation is to assess the cost and greenhouse gas reduction benefits of substituting relatively high volumes of biomass in coal. Two scenarios for cofiring up to 20% biomass with coal (on a lower heating value basis) are presented; (1) woody biomass in central Alabama where Southern Pine is currently produced for the wood products and paper industries, and (2) purpose-grown switchgrass in the Ohio River Valley. These examples are representative of regions where renewable biomass growth rates are high in correspondence with major U.S. heartland power production. While these scenarios may provide a realistic reference for comparing the relative benefits of using a high volume of biomass for power production, this evaluation is not intended to be an analysis of policies concerning renewable portfolio standards or the optimal use of biomass for energy production in the U.S.

A Novel Approach to Maximize Waste Recovery in a Life Support System

NASA has been evaluating closed-loop atmosphere revitalization architectures that include carbon dioxide (CO2) reduction technologies. The CO2 and steam (H2O) coelectrolysis process is one of the reduction options that NASA has investigated. Utilizing recent advances in the fuel cell technology sector, the Idaho National Laboratory, INL, has developed a CO2 and H2O co-electrolysis process to produce oxygen and syngas (carbon monoxide (CO) and hydrogen (H2) mixture) for terrestrial (energy production) application. The technology is a combined process that involves steam electrolysis, CO2 electrolysis, and the reverse water gas shift (RWGS) reaction. Two process models were developed to evaluate novel approaches for energy storage and resource recovery in a life support system. In the first model, products from the INL co-electrolysis process are combined to produce methanol fuel. In the second, co-electrolysis products are separated with a pressure swing adsorption (PSA) process. In both models the fuels are burned with added oxygen to produce H2O and CO2, the original reactants. For both processes, the overall power increases as the syngas ratio, H2/CO, increases because more water is needed to produce additional hydrogen at a set CO2 incoming flow rate. The power for the methanol cases is less than pressure swing adsorption, PSA, because heat is available from the methanol reactor to preheat the water and carbon dioxide entering the co-electrolysis process.