Kenneth Weil - Academia.edu (original) (raw)

Papers by Kenneth Weil

Ceramic Engineering and Science Proceedings

One of the challenges in developing a useful ceramic joining technique is in producing a joint th... more One of the challenges in developing a useful ceramic joining technique is in producing a joint that offers good strength under high temperature and highly oxidizing operating conditions. Unfortunately many of the commercially available active metal ceramic brazing alloys exhibit oxidation behaviors which are unacceptable for use in a high temperature application. We have developed a new approach to ceramic brazing, referred to as air brazing, that employs an oxide wetting agent dissolved in a molten noble metal solvent, in this case CuO in Ag, such that acceptable wetting behavior occurs on a number of ceramic substrates. In an effort to explore how to increase the operating temperature of this type of braze, we have investigated the effect of ternary palladium additions on the wetting characteristics of our standard Ag-CuO air braze composition

Journal of The Electrochemical Society, 2003

Over the past several years, advances in the design and fabrication of planar solid oxide fuel ce... more Over the past several years, advances in the design and fabrication of planar solid oxide fuel cells (SOFCs) have led to a steady reduction in the temperatures necessary for their operation. Consequently, it appears more realistic now to use low cost heat-resistant ...

International Journal of Hydrogen Energy, 2008

The projected doubling of world energy consumption within the next 50 years, coupled with the fos... more The projected doubling of world energy consumption within the next 50 years, coupled with the fossil fuel constrains and the growing concern over environment, has spurred a dramatic worldwide growth in research and development activities associated with clean power technologies. Such technologies may include, but are not limited to, various fuel cells (PEMFC, SOFC, MCFC, etc.), power generation from renewable sources of solar and wind, and clean coal power generation coupled with CO 2 capture and sequestration, as well as hydrogen production, delivery, and storage. Concomitant with the overall commitment to power system development and commercialization, there have been increasing interests in the materials that are employed in system componentry. These materials perform varied functions under operating conditions that are often aggressive in these applications. Thus improved stability and performance in such environments are essential to simultaneously attaining high system power, efficiency, and reliability. This issue of the International Journal of Hydrogen Energy contains selected papers presented at the symposium on ''Materials in Clean Power Systems II: Fuel Cells, Solar, and Hydrogen Based Technologies'' held at the 2007 (136th) TMS Annual Conference and Exposition in Orlando, Florida, USA. The symposium was organized to provide a forum for scientists and engineers from academia, industry, and government laboratories worldwide to present and discuss the latest advancements in materials being developed for clean power systems, including emerging applications, material property requirements, degradation issues, compositional and microstructural modifications for improved stability and performance, and developments in material processing for commercialization. As such, the papers in this special issue reflect a wide range of scientific and technological topics in this field: Structural materials for applications such as interconnections, sealing and packaging in fuel cells (SOFCs, MCFCs, PEMFCs, and others).

International Journal of Hydrogen Energy, 2011

hydrogen.energy.gov

K. Scott Weil (Primary Contact), Jin Yong Kim, Gordon Xia, and Z. Gary Yang Pacific Northwest Nat... more K. Scott Weil (Primary Contact), Jin Yong Kim, Gordon Xia, and Z. Gary Yang Pacific Northwest National Laboratory PO Box 999 Richland, WA 99352 Phone: (509) 375-6796; Fax: (509) 375-2186; E-mail: scott.weil@pnl.gov ... Collaborating Co-authors: Steve Chang and ...

Ceramic Engineering and Science Proceedings

ABSTRACT This paper describes the effects of small palladium additions on the phase equilibria in... more ABSTRACT This paper describes the effects of small palladium additions on the phase equilibria in the Ag–CuOx system. Below a concentration of 5 mol%, palladium was found to increase the temperature of the eutectic reaction present in the pseudobinary system, but have little effect on a higher temperature monotectic reaction. However once enough palladium was added to increase the pseudoternary solidus temperature to that of the lower boundary for this three–phase field (∼970°C), the lower boundary begins to increase in temperature as well. The addition of palladium also causes the original eutectic point to move to lower silver concentrations, which also causes a convergence of the two new three–phase fields, CuOx + L1 + L2 and CuOx + α + L1This suggests that with higher palladium concentrations, a peritectic reaction, αa + L1 + L2 CuOx, may eventually be observed in the system.

Ceramic Engineering and Science Proceedings

ABSTRACT SummaryA key issue in developing commercially viable planar solid oxide fuel cell stacks... more ABSTRACT SummaryA key issue in developing commercially viable planar solid oxide fuel cell stacks is appropriate seal design. We are currently developing an alternative approach to rigid and compressive seal designs that conceptually combines advantages of both techiques, including hermeticity, mechanical integrity, and minimization of interfacial stresses in either of the joint substrate materials, particulary the ceramic. The new seal relies on a plastically deformable metal seal; one that offers a quasi-dynamic mechanical response in that it is adherent to both sealing surfaces, i. e. non-sliding, but readily yields or deforms under thermally generated stresses. In this way, we hope to mitigate the development of stresses in the adjacent ceramic and metal components even when a significant difference in thermal expansion exists between the two materials. Here we employ finite element modeling to assess the potential thermal cycling performance of this design, specifically as it pertains to sealing components with vastly different thermal expansion properties.

Advances in Ceramic Coatings and Ceramic-Metal Systems: Ceramic Engineering and Science Proceedings, Volume 26, Number 3

... All samples were prepared using 99.9% purity Ag foil from Lucas-Milhaupt Inc (Cudahy, WA), an... more ... All samples were prepared using 99.9% purity Ag foil from Lucas-Milhaupt Inc (Cudahy, WA), and 99.8% purity V205 powder from Alfa Aesar (Ward HilL MA). ... I3E. J. Pavlina," Development of Liquid Ag/CuO and Ag/VjOj Braze Alloys for Electroding Multi-layer PZT Devices," Sr. ...

SSRN Electronic Journal

Abstract When encumbered property is sold, the taxation of that sale is different if the sale inv... more Abstract When encumbered property is sold, the taxation of that sale is different if the sale involves recourse debt as opposed to nonrecourse debt. This difference raises an intriguing question: when debt changes from recourse to nonrecourse, or vice versa, which rules will control? Examples of when debt changes from recourse to nonrecourse, or vice versa, include bankruptcy discharges, nonjudicial foreclosures in some states with deficiency statutes, some short sales in deficiency states, and the operation of section 1111(b) of the Bankruptcy Code. The Cottage Savings regulations, Regulation section 1.1001-3, have specific provisions designed to address what happens when debt changes from recourse to nonrecourse, or vice versa. These regulations are sometimes helpful to creditors (e.g. , elections under section 1111(b)(2) of the Bankruptcy Code). Sometimes, they appear punitive to debtors (e.g. , the mandatory conversion of recourse debt into nonrecourse debt in Chapter 11). And, sometimes, they do not provide an answer (e.g. , short sales and nonjudicial foreclosures in deficiency states). The Author believes that when recourse debt is converted to nonrecourse debt by operation of a discharge in bankruptcy, there should be a discharge of indebtedness event, and thereafter, the nonrecourse rules would apply, albeit with the nonrecourse debt reduced by the amount of the debt discharged. As a result, after discharge, the nonrecourse debt would be reduced to the fair market value of the collateral. Upon a subsequent sale, the amount realized by the debtor would be the fair market value of the property (or the new taxvalue of the debt if the property declines in value). The current rule, with the amount realized equaling the old face value of the debt, would no longer apply. This change would put an end to the punitive gains resulting from the current nonrecourse-sale rules. Unfortunately, this proposal is probably not administratively feasible.

ECS Proceedings Volumes

... Here we discuss two such methods that may have potential application in pSOFCs. Publisher, SC... more ... Here we discuss two such methods that may have potential application in pSOFCs. Publisher, SC Singhal and J Mizusaki; Electrochemical Society, Pennington, NJ, United States(US). Country of Publication, United States. Language, English. Update Date, 2010 Apr 19. ...

The method for forming a metal part by using the raw material composition and the powder metallur... more The method for forming a metal part by using the raw material composition and the powder metallurgy technique comprises mixing the metal or metal compound and the aromatic new binder systems. Compositions of the new material comprises a metal powder and an aromatic binder system. Aromatic binder system may comprise an aromatic and contain a lubricant, a surfactant, and a polymer as a further additive. Metal powders, in particular to the highly reactive metal, metal, metal compounds, and metal alloys. Method for forming a metal part comprises the steps of supplying the metal powder and the binder aromatic system to produce a new raw material and mixed. The method, using a powder metallurgy forming techniques such as metal injection molding further comprises machining the metal part to new raw material. The metal molded parts through the present invention have an increase in the oxygen and carbon content of 0.2 wt% or less for the metal powder used to manufacture the part.

Weil/Surfaces, 2012

Mixed ionic/electronic conducting perovskite oxides such as lanthanum strontium cobalt ferrite (L... more Mixed ionic/electronic conducting perovskite oxides such as lanthanum strontium cobalt ferrite (LSCF) are strong candidates for potential use in a number of electrochemical devices, including gas separation membranes and solid oxide fuel cells (SOFC). Underlying the excitement over the these novel ceramics is the engineering challenge of effectively incorporating them into practical devices. Taking full advantage of the unique properties of advanced ceramics such as mixed conducting oxides depends in large part on being able to develop reliable joining techniques. Earlier studies have indicated that Ag-CuO reactive air braze (RAB) compositions are effective in joining to LSCF. Meanwhile, it has been found that small additions of as little as 0.5 mol% titanium oxide to Ag-CuO RAB compositions cause a dramatic increase in the wettability of RAB on many oxide ceramic surfaces. Therefore the wettabilty of Ag-CuO-TiO2 brazes on LSCF substrates will be examined and the flexural strength, microstructure, and conductivity of joints in LSCF made using Ag-CuO-TiO2 brazes will be discussed. Long-term aging effects on conductivity and microstructure will also be presented.

Ceramic Transactions Series, 2011

Weil/Surfaces, 2012

The oxidation behavior of a commercially available ceramic-to-metal braze alloy, Gold ABA, was in... more The oxidation behavior of a commercially available ceramic-to-metal braze alloy, Gold ABA, was investigated to evaluate its potential use in joining solid-state electrochemical device components. High temperature air exposure studies were performed on as-received braze alloy foils, on braze couples prepared with yttria-stabilized zirconia (YSZ) and 430 stainless steel substrates, and on brazed YSZ/430 joints. The results of our investigations demonstrate that the substrates can play an important role in determining the overall oxidation resistance of the brazed joint.

Lewinsohn/Advances, 2006

ABSTRACT For Abstract see ChemInform Abstract in Full Text.

Ceramic Engineering and Science Proceedings

One of the challenges in developing a useful ceramic joining technique is in producing a joint th... more One of the challenges in developing a useful ceramic joining technique is in producing a joint that offers good strength under high temperature and highly oxidizing operating conditions. Unfortunately many of the commercially available active metal ceramic brazing alloys exhibit oxidation behaviors which are unacceptable for use in a high temperature application. We have developed a new approach to ceramic brazing, referred to as air brazing, that employs an oxide wetting agent dissolved in a molten noble metal solvent, in this case CuO in Ag, such that acceptable wetting behavior occurs on a number of ceramic substrates. In an effort to explore how to increase the operating temperature of this type of braze, we have investigated the effect of ternary palladium additions on the wetting characteristics of our standard Ag-CuO air braze composition

Journal of The Electrochemical Society, 2003

Over the past several years, advances in the design and fabrication of planar solid oxide fuel ce... more Over the past several years, advances in the design and fabrication of planar solid oxide fuel cells (SOFCs) have led to a steady reduction in the temperatures necessary for their operation. Consequently, it appears more realistic now to use low cost heat-resistant ...

International Journal of Hydrogen Energy, 2008

The projected doubling of world energy consumption within the next 50 years, coupled with the fos... more The projected doubling of world energy consumption within the next 50 years, coupled with the fossil fuel constrains and the growing concern over environment, has spurred a dramatic worldwide growth in research and development activities associated with clean power technologies. Such technologies may include, but are not limited to, various fuel cells (PEMFC, SOFC, MCFC, etc.), power generation from renewable sources of solar and wind, and clean coal power generation coupled with CO 2 capture and sequestration, as well as hydrogen production, delivery, and storage. Concomitant with the overall commitment to power system development and commercialization, there have been increasing interests in the materials that are employed in system componentry. These materials perform varied functions under operating conditions that are often aggressive in these applications. Thus improved stability and performance in such environments are essential to simultaneously attaining high system power, efficiency, and reliability. This issue of the International Journal of Hydrogen Energy contains selected papers presented at the symposium on ''Materials in Clean Power Systems II: Fuel Cells, Solar, and Hydrogen Based Technologies'' held at the 2007 (136th) TMS Annual Conference and Exposition in Orlando, Florida, USA. The symposium was organized to provide a forum for scientists and engineers from academia, industry, and government laboratories worldwide to present and discuss the latest advancements in materials being developed for clean power systems, including emerging applications, material property requirements, degradation issues, compositional and microstructural modifications for improved stability and performance, and developments in material processing for commercialization. As such, the papers in this special issue reflect a wide range of scientific and technological topics in this field: Structural materials for applications such as interconnections, sealing and packaging in fuel cells (SOFCs, MCFCs, PEMFCs, and others).

International Journal of Hydrogen Energy, 2011

hydrogen.energy.gov

K. Scott Weil (Primary Contact), Jin Yong Kim, Gordon Xia, and Z. Gary Yang Pacific Northwest Nat... more K. Scott Weil (Primary Contact), Jin Yong Kim, Gordon Xia, and Z. Gary Yang Pacific Northwest National Laboratory PO Box 999 Richland, WA 99352 Phone: (509) 375-6796; Fax: (509) 375-2186; E-mail: scott.weil@pnl.gov ... Collaborating Co-authors: Steve Chang and ...

Ceramic Engineering and Science Proceedings

ABSTRACT This paper describes the effects of small palladium additions on the phase equilibria in... more ABSTRACT This paper describes the effects of small palladium additions on the phase equilibria in the Ag–CuOx system. Below a concentration of 5 mol%, palladium was found to increase the temperature of the eutectic reaction present in the pseudobinary system, but have little effect on a higher temperature monotectic reaction. However once enough palladium was added to increase the pseudoternary solidus temperature to that of the lower boundary for this three–phase field (∼970°C), the lower boundary begins to increase in temperature as well. The addition of palladium also causes the original eutectic point to move to lower silver concentrations, which also causes a convergence of the two new three–phase fields, CuOx + L1 + L2 and CuOx + α + L1This suggests that with higher palladium concentrations, a peritectic reaction, αa + L1 + L2 CuOx, may eventually be observed in the system.

Ceramic Engineering and Science Proceedings

ABSTRACT SummaryA key issue in developing commercially viable planar solid oxide fuel cell stacks... more ABSTRACT SummaryA key issue in developing commercially viable planar solid oxide fuel cell stacks is appropriate seal design. We are currently developing an alternative approach to rigid and compressive seal designs that conceptually combines advantages of both techiques, including hermeticity, mechanical integrity, and minimization of interfacial stresses in either of the joint substrate materials, particulary the ceramic. The new seal relies on a plastically deformable metal seal; one that offers a quasi-dynamic mechanical response in that it is adherent to both sealing surfaces, i. e. non-sliding, but readily yields or deforms under thermally generated stresses. In this way, we hope to mitigate the development of stresses in the adjacent ceramic and metal components even when a significant difference in thermal expansion exists between the two materials. Here we employ finite element modeling to assess the potential thermal cycling performance of this design, specifically as it pertains to sealing components with vastly different thermal expansion properties.

Advances in Ceramic Coatings and Ceramic-Metal Systems: Ceramic Engineering and Science Proceedings, Volume 26, Number 3

... All samples were prepared using 99.9% purity Ag foil from Lucas-Milhaupt Inc (Cudahy, WA), an... more ... All samples were prepared using 99.9% purity Ag foil from Lucas-Milhaupt Inc (Cudahy, WA), and 99.8% purity V205 powder from Alfa Aesar (Ward HilL MA). ... I3E. J. Pavlina," Development of Liquid Ag/CuO and Ag/VjOj Braze Alloys for Electroding Multi-layer PZT Devices," Sr. ...

SSRN Electronic Journal

Abstract When encumbered property is sold, the taxation of that sale is different if the sale inv... more Abstract When encumbered property is sold, the taxation of that sale is different if the sale involves recourse debt as opposed to nonrecourse debt. This difference raises an intriguing question: when debt changes from recourse to nonrecourse, or vice versa, which rules will control? Examples of when debt changes from recourse to nonrecourse, or vice versa, include bankruptcy discharges, nonjudicial foreclosures in some states with deficiency statutes, some short sales in deficiency states, and the operation of section 1111(b) of the Bankruptcy Code. The Cottage Savings regulations, Regulation section 1.1001-3, have specific provisions designed to address what happens when debt changes from recourse to nonrecourse, or vice versa. These regulations are sometimes helpful to creditors (e.g. , elections under section 1111(b)(2) of the Bankruptcy Code). Sometimes, they appear punitive to debtors (e.g. , the mandatory conversion of recourse debt into nonrecourse debt in Chapter 11). And, sometimes, they do not provide an answer (e.g. , short sales and nonjudicial foreclosures in deficiency states). The Author believes that when recourse debt is converted to nonrecourse debt by operation of a discharge in bankruptcy, there should be a discharge of indebtedness event, and thereafter, the nonrecourse rules would apply, albeit with the nonrecourse debt reduced by the amount of the debt discharged. As a result, after discharge, the nonrecourse debt would be reduced to the fair market value of the collateral. Upon a subsequent sale, the amount realized by the debtor would be the fair market value of the property (or the new taxvalue of the debt if the property declines in value). The current rule, with the amount realized equaling the old face value of the debt, would no longer apply. This change would put an end to the punitive gains resulting from the current nonrecourse-sale rules. Unfortunately, this proposal is probably not administratively feasible.

ECS Proceedings Volumes

... Here we discuss two such methods that may have potential application in pSOFCs. Publisher, SC... more ... Here we discuss two such methods that may have potential application in pSOFCs. Publisher, SC Singhal and J Mizusaki; Electrochemical Society, Pennington, NJ, United States(US). Country of Publication, United States. Language, English. Update Date, 2010 Apr 19. ...

The method for forming a metal part by using the raw material composition and the powder metallur... more The method for forming a metal part by using the raw material composition and the powder metallurgy technique comprises mixing the metal or metal compound and the aromatic new binder systems. Compositions of the new material comprises a metal powder and an aromatic binder system. Aromatic binder system may comprise an aromatic and contain a lubricant, a surfactant, and a polymer as a further additive. Metal powders, in particular to the highly reactive metal, metal, metal compounds, and metal alloys. Method for forming a metal part comprises the steps of supplying the metal powder and the binder aromatic system to produce a new raw material and mixed. The method, using a powder metallurgy forming techniques such as metal injection molding further comprises machining the metal part to new raw material. The metal molded parts through the present invention have an increase in the oxygen and carbon content of 0.2 wt% or less for the metal powder used to manufacture the part.

Weil/Surfaces, 2012

Mixed ionic/electronic conducting perovskite oxides such as lanthanum strontium cobalt ferrite (L... more Mixed ionic/electronic conducting perovskite oxides such as lanthanum strontium cobalt ferrite (LSCF) are strong candidates for potential use in a number of electrochemical devices, including gas separation membranes and solid oxide fuel cells (SOFC). Underlying the excitement over the these novel ceramics is the engineering challenge of effectively incorporating them into practical devices. Taking full advantage of the unique properties of advanced ceramics such as mixed conducting oxides depends in large part on being able to develop reliable joining techniques. Earlier studies have indicated that Ag-CuO reactive air braze (RAB) compositions are effective in joining to LSCF. Meanwhile, it has been found that small additions of as little as 0.5 mol% titanium oxide to Ag-CuO RAB compositions cause a dramatic increase in the wettability of RAB on many oxide ceramic surfaces. Therefore the wettabilty of Ag-CuO-TiO2 brazes on LSCF substrates will be examined and the flexural strength, microstructure, and conductivity of joints in LSCF made using Ag-CuO-TiO2 brazes will be discussed. Long-term aging effects on conductivity and microstructure will also be presented.

Ceramic Transactions Series, 2011

Weil/Surfaces, 2012

The oxidation behavior of a commercially available ceramic-to-metal braze alloy, Gold ABA, was in... more The oxidation behavior of a commercially available ceramic-to-metal braze alloy, Gold ABA, was investigated to evaluate its potential use in joining solid-state electrochemical device components. High temperature air exposure studies were performed on as-received braze alloy foils, on braze couples prepared with yttria-stabilized zirconia (YSZ) and 430 stainless steel substrates, and on brazed YSZ/430 joints. The results of our investigations demonstrate that the substrates can play an important role in determining the overall oxidation resistance of the brazed joint.

Lewinsohn/Advances, 2006

ABSTRACT For Abstract see ChemInform Abstract in Full Text.