Engineering Commons^™

A Critical Review Of High Entropy Alloys (Heas) And Related Concepts, D.B. Miracle, O.N. Senkov

Beyond Nickel-Based Superalloys II

The field of high entropy alloys (HEAs) is barely 10 years old. It has stimulated new ideas and has inspired the exploration of the vast composition space. Here we give a critical review of this body of work, with the intent of summarizing key findings, uncovering major trends and providing guidance for future efforts. Based on detailed analysis, the following major results emerge. An intense focus is apparent on alloys based on first row transition metal elements. These efforts have discovered an extended, single-phase solid solution phase field and are exploring the extent and properties of this phase field. As …

Towards Nanoindentation At Application-Relevant Temperatures – A Study On Cmsx-4 Alloy And Amdry-386 Bond Coat, James Gibson, Sebastian Schröders, Christoffer Zehnder, Sandra Korte-Kerzel

Beyond Nickel-Based Superalloys II

With nickel-based superalloys reaching their fundamental limit in high-temperature applications, new alloys are required with improved mechanical properties. Small-scale mechanical testing – particularly nanoindentation – is of great benefit to alloy development, allowing hardness and modulus to be measured on small volumes of newly-developed materials.

We show that it is now possible to carry out such tests in vacuum up to 1000˚C, paving the way for candidate alloys and coatings to be tested at operation-relevant conditions. In this work, a <001> oriented single-crystal CMSX4 sample and a 200 µm Amdry-386 bond coat were tested using a modified MicroMaterials NanoTest indenter. 1 …

Γ/Γ' Co-Base Superalloys – New High Temperature Materials Beyond Ni-Base Superalloys?, Steffen Neumeier, Christopher H. Zenk, Lisa P. Freund, Mathias Göken

Beyond Nickel-Based Superalloys II

In 2006 a new L1₂ phase, Co₃(Al,W), was discovered in the Co-Al-W system which has led to the development of novel Co-base superalloys with g/g¢ microstructures similar to those of the well-established Ni-base superalloys. First investigations on simple ternary alloys could show that these Co-Al-W based alloys exhibit higher solidus temperatures and show less segregations after casting compared to typical Ni-base superalloys. This leads to the question whether this g/g¢ Co-base superalloys can be regarded as new class of high temperature materials that can compete with or even supersede established Ni-base superalloys.

In the first part of …

Microstructural Analysis And High Temperature Creep Of Mo-9si-8b Alloys With Al And Ge Additions, Peter Kellner, Rainer Völkl, Uwe Glatzel

Beyond Nickel-Based Superalloys II

Refractory metals and their alloys show potential for high temperature applications, due to the increased melting point and creep resistance. Spark plasma sintering technology as well as argon arc melting is used to prepare quaternary and quinternary Mo-9Si-8B-xAl-yGe (x is 0 or 2; y is 0 or 2) samples. Compositions are stated in at.%. All the compositions consist of a Mo solid solution (α-Mo) and two intermetallic phases: Mo₃Si (A15) and Mo₅SiB₂ (T₂). On the one hand, no zirconium is added to the alloys to avoid evaporation of MoO₃ due to the …

Enhanced Oxidation Resistance Of Ti-Rich Mo-Si-B Alloys By Pack-Cementation Process, Camelia Gombola, Daniel Schliephake, Martin Heilmaier, John H. Perepezko

Beyond Nickel-Based Superalloys II

To increase efficiency by higher combustion temperatures of aircraft engines and energy generation, new high temperature materials are inevitable. Mo-Si-B alloys for example satisfy several requirements such as good oxidation and creep resistance. Recently, novel Ti-rich Mo-Si-B alloys have shown an increased creep resistance compared to Ti-free Mo-Si-B alloys by the formation of Ti-silicide precipitates during processing. However, due to the formation of a duplex SiO₂ – TiO₂ oxide layer, where fast inwards diffusion of oxygen takes place, the oxidation resistance is poor.

In this study we show that oxidation resistance of Mo-Si-B-Ti alloys can be enhanced drastically …

Microstructural Stability Of Co-Re-Cr-Ta-C Alloy Strengthened By Tac Precipitates, Debashis Mukherji, Ralph Gilles, Lukas Karge, Pavel Strunz, Přemysl Beran, Joachim Rösler

Beyond Nickel-Based Superalloys II

It is becoming increasingly clear that new materials that can operate at substantially higher temperatures than Ni-base superalloys are needed for future gas turbines. High melting Co-Re-Cr based alloy strengthened by carbides, particularly the MC type carbide, shows promise [1]. A fine dispersion of globular TaC precipitate is exploited for this purpose. Additionally Cr, which is mainly added to improve oxidation resistance, also stabilizes lamellar M₂₃C₆ type Cr carbide. The microstructure of a Co-Re-Cr-Ta-C alloy with the two types of carbides is seen in Fig. 1.

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Mo-9si-8b Alloys With Additons Of Zr – Microstructure And Creep Properties, Uwe Glatzel, Christian Hochmuth, Rainer Völkl

Beyond Nickel-Based Superalloys II

Three phase Mo-9Si-8B (at.%) alloys are a prominent example for a potential new high temperature structural material. Due to their high melting point and excellent creep resistance. In this study the effect of Zr addition (0…4 at.%) on the microstructure and creep properties of Mo-9Si-8B (at.%) alloys is investigated. Two powder metallurgical processes, hot isostatic pressing (HIP) and spark plasma sintering (SPS), are used to prepare specimens. The resulting microstructures are examined using SEM and TEM analysis. SPS alloys exhibit smaller grain sizes and fewer oxides compared to the HIP alloys, because of the oxygen availability during HIP. The more …

Microstructure And Creep Resistance Of Ti-Rich Mo + Mo5si3 + Mo5sib2 Alloys, Daniel Schliephake, Martin Heilmaier

Beyond Nickel-Based Superalloys II

New materials are necessary to increase efficiency of power generation and aircraft engines by higher combustion temperatures. Recently, it was found that alloying with high amounts of Ti replaces Mo₃Si by Mo₅Si₃ and stabilizes the phase field Mo + Mo₅Si₃ + Mo₅SiB₂, which could be beneficial for higher oxidation resistance, since Mo₅Si₃ is more oxidation resistant than Mo₃Si. Additional, Ti-rich Mo-Si-B alloys show an increased creep resistance compared to Ti-free Mo-Si-B alloys and a significant reduction in the alloy density. However, using the …

Design Of Gamma-Prime-Strengthened Co-Based Superalloys: Where We Are And Where We Need To Go, Eric A. Lass

Beyond Nickel-Based Superalloys II

Since the first report of a stable two-phase g-g’ (FCC-L12) phase field in ternary Co-Al-W in 2006, there has been significant research effort in developing this new class of Co-based g’-strengthened superalloys for high temperature applications. Much of the focus has been on characterizing and improving high temperature properties such as the g’ solvus temperature, high temperature strength and creep resistance, corrosion and oxidation behavior. Much of this work has been conducted experimentally utilizing the wealth of knowledge of Ni-based superalloys gathered over the last several decades. Efforts into developing effective modeling tools, such as thermodynamic and diffusion databases, have …

Improving The Oxidation Resistance Of Refractory Metals Via Aluminum Diffusion Coatings And Halogen Effect, A.S. Ulrich, M.C. Galetz

Beyond Nickel-Based Superalloys II

Recently, refractory metals and their alloys have received increasing attention for the purpose of substituting Ni-based single crystal superalloys. Compared to commonly used materials, refractory metals have significantly higher melting points while their mechanical properties seem adequate at high temperatures. The main challenge for their application is, that refractory metals show low oxidation resistances at elevated temperatures. Aluminum diffusion layers are promising coatings to suppress harmful oxidation by forming a protective oxide layer. This study deals with the application of such aluminum reservoir layers and with the investigation of their protective properties. Four different unalloyed refractory metals, molybdenum, tantalum, tungsten …

Conference Program, Howard J. Stone

Beyond Nickel-Based Superalloys II

No abstract provided.

Plant-Based Technologies To Enable Rapid Response To Ebola Outbreak, Jerzy Karczewski, Vidadi Yusibov

Vaccine Technology VI

Ebola is a rare and deadly disease caused by infection with a strain of Ebola virus (Zaire, Sudan or Marburg). Ebola is spread through a direct contact with body fluids of infected patients. The recent Ebola outbreak affected multiple countries in West Africa and clearly demonstrated a need for development of technologies enabling production of adequate supply of vaccines and therapeutics to treat infected patients. We have undertaken efforts to develop methods and produce plant-based recombinant vaccine as well as a series of monoclonal antibodies to fight Ebola infection.

Several approaches were carried out to develop vaccines based on recombinant …

Development, Manufacturing, And Supply Of Msd’S Ebola Vaccine, Jeffrey T. Blue

Vaccine Technology VI

Ebola was first discovered in 1976 and is a member of the filoviridae family of viruses. There are multiple strains of Ebola and infection can lead to hemorrhagic fever and death. In March 2014, a historic Ebola outbreak occurred in three Western African countries, Guinea, Liberia, and Sierra Leone. Over 28,000 cases were reported and led to more than 11,000 deaths, more than ten times the amount of cases compared to all past outbreaks combined. On August 8^th 2014, the World Health Organization declared a Public Health Emergency of International Concern (PHEIC). Merck Sharp & Dohme (MSD) partnering with …

Carboncycle And Other Profitable Strategies For Air Capture Of Co2, Deane Little

CO2 Summit II: Technologies and Opportunities

Development of an effective and economically viable strategy for air capture of CO2 would be a game-changing development in the fight against global warming. If widely adopted such a process would allow “chemostatting” the atmosphere at sustainable CO2 levels and might not require widespread social change in how we use fossil fuels. Unfortunately the concept that air capture of CO2 “doesn’t work” has taken hold in academic and policy circles, based on the assumption that such a process is inherently expensive and results in no useful products. In fact, air capture of CO2 can be profitable and offers fundamental advantages …

Fulfilling The Promise Of The Paris Agreement: The Role Of Efficiency And Renewable Energy, Chuck Kutscher

CO2 Summit II: Technologies and Opportunities

Renewable energy, energy policy, energy efficiency, buildings

The rapid large-scale deployment of efficiency and renewable energy technologies is crucial to meeting the goals of the COP21 agreement. Key to achieving this is transitioning to zero-carbon cities comprised of highly efficient buildings powered by renewable electricity. This presentation will survey the current efficiency and renewable energy research underway at the National Renewable Energy Laboratory with special attention paid to zero-carbon buildings and the challenges of developing a renewable energy electric grid.

Development Of The First Internationally Accepted Standard For Geologic Storage Of Carbon Dioxide Utilizing Enhanced Oil Recovery (Eor) Under The International Standards Organization (Iso) Technical Committee Tc-265, Steven Carpenter

CO2 Summit II: Technologies and Opportunities

The Carbon Capture, Utilization, and Storage (CCUS) industry is lacking standardization and therefore the ability to allow CCUS projects to advance as Clean Development Mechanism (CDM) or to be considered for any type of carbon management or accounting scheme is also hindered. An international effort between the United States and Canada, funded by the International Performance Assessment Centre for Geologic Storage of Carbon Dioxide (IPAC-CO2 Research Inc.), and managed by CSA Standards, have developed the first internationally recognized Standard for the geologic storage of carbon dioxide (Z-741). The Z-741 Standard has been adopted by the Standards Council of Canada (SCC) …

Emissions And Deforestation Associated With Household Energy Use: A Case Of The Thulamela Local Municipality, South Africa, Se Uhunamure, Ns Nethengwe, A Musyoki

CO2 Summit II: Technologies and Opportunities

Fuel wood is regarded as a major source of energy around the world, particularly in developing nations forming part of the energy mix. Most rural communities around the world, consider forests as the repository of stored energy. The study focused on the role of fuel wood in deforestation and the emissions of greenhouse gases (GHG) in the Thulamela local municipality in South Africa. Information regarding the fuel wood consumption was collected during a manual field survey of 200 households in four villages in the municipality using questionnaires and interviews. The carbon dioxide (CO₂) emissions were calculated using the …

Conference Program, Engineering Conferences International

CO2 Summit II: Technologies and Opportunities

No abstract provided.

Microstructure And Mechanical Properties Of Spark Plasma Sintered Tungsten-Copper– Zinc Composites, Thabiso Langa, S. Diouf

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Tungsten/Copper (W/Cu) composites, generally used for applications whereby the combination of high heat resistance, high electrical and thermal conductivity and low thermal expansion is required, are suitable for hard working conditions such as intensive electrical sparks, gouging spark erosion, surface melting, welding, material transfer etc. However, the large disparity between the melting point of tungsten (3410 °C) and that of copper (1083 °C) make their production through traditional processes very difficult. Furthermore the difficulty of approaching near theoretical densities even by using liquid phase sintering, due to the negligible mutual solubility of the constituents and high wetting angle of liquid …

Final Program, Kathy Chan

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

No abstract provided.

Designing A Microbial Cultivation Platform For Continuous Biopharmaceutical Production, Nicholas Mozdzierz, Kerry Love, Alan Stockdale, John Clark, Noelle Colant, Christopher Love

Integrated Continuous Biomanufacturing II

The existing biopharmaceutical manufacturing paradigm is poorly suited to produce biologic drugs on demand at a point-of-care. Generally, commercial-scale (~2,000 - 10,000 L) manufacturing using fed-batch cultivation and fixed stainless-steel infrastructure is concentrated in developed nations and results in process cycle times on the order of weeks to months.^1,2 Coupled with the complex logistical challenges associated with continuous “plant-to-patient” cold-chains, the geographically biased nature of therapeutic protein production today can limit access to biologic drugs in developing areas of the world.³ There is an opportunity to create technologies capable of rapidly generating biopharmaceuticals in situ in emergency situations, …

Nanomechanical Testing Of Ods Steels Irradiated With 1 Mev/Amu Heavy Ions, Kateryna Kornieieva, Vladimir Skuratov, Alexander Sohatsky, Jacques O'Connell, Yuri Golovin, Victor Korenkov, Jan Neethling

Nanomechanical Testing in Materials Research and Development V

Heavy ion beams with high damage production rate are widely used to evaluate radiation tolerance of promising nuclear reactor materials, such as oxide dispersion strengthened (ODS) alloys, including their mechanical properties. Since typical ion projected ranges do not exceed 1 micron, nanoindentation technique is the most convenient method for examination of irradiated materials.

In present work we report data on radiation hardening of several ODS steels irradiated with 107 MeV Kr and 167 MeV Xe ions. Some samples were irradiated trough the special Al-foil filter in order to obtain the unfolding damage profile on the surface. The post-irradiation testing steels …

Suitability Of Geoscan-M Elemental Analyser For Phosphate Rock, H. Kurth, Derek Griffiths

Beneficiation of Phosphates VII

No abstract provided.

Phosphate Beneficiation With Novel Collectors For Direct And Reverse Flotation: Beyond Low Cost Fatty Acids, Pablo Dopico

Beneficiation of Phosphates VII

No abstract provided.

A Tailor Made Approach For The Beneficiation Of Phosphate Rock, Leonid Lisiansky, Mike Baker, Keren Larmour-Ship, Olga Elyash

Beneficiation of Phosphates VII

Tenova Bateman Technologies (TBT), part of Tenova Mining & Minerals is known as a provider of advanced process technologies in solvent extraction, phosphate beneficiation and fertilizer production.

TBT has participated in a number of phosphate projects and offers a comprehensive range of phosphate treatment technologies: from beneficiation to the production of purified phosphoric acid and downstream salts.

The beneficiation of phosphate rock can often be simplified and made more economic by taking into account the distribution of P₂O₅ and impurities as a function of their deportment between the size fractions resulting from mined and comminuted sedimentary phosphates. …

Shotcrete Education And Nozzlemen Certification In North America, Marc Jolin, J. Nehasil, C. Hanskat

Shotcrete for Underground Support XII

No abstract provided.

Quality Control For Wet-Mix Fiber Reinforced Shotcrete In Ground Support, Lihe (John) Zhang, Dudley R. Morgan

Shotcrete for Underground Support XII

No abstract provided.

Transport Properties Of Wet-Mix Shotcrete, Lihe (John) Zhang, Dudley R. Morgan

Shotcrete for Underground Support XII

No abstract provided.

A Model For Magnetic Drug Targeting In A Permeable Microvessel With Spherical Porous Carrier Particles, Precious Sibanda, Sachin Shaw

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

We present a mathematical model for targeting a drug at malignant tissue cells in a permeable microvessel. The drug molecules are transported in carrier particles which are assumed to be porous spheres. This mode of drug delivery is non-invasive and has less toxic effects on healthy cells and tissues. The microvessel tube (see Figure 1) is subdivided into three regions, the outer endothelial glycocalyx layer where the blood has a Newtonian character, and a core and plug regions where the blood flow is described using a non-Newtonian Casson fluid model which is suitable for microvessels of radius 5mμ. Targeting is …

Comparative Analysis Of Geometric Models For Predicting The Dynamic Specific Surface Of Foamlike Media, Sonia Woudberg, Francois Smit

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

An adaptable geometric pore-scale model is proposed for predicting the specific surface area of actual foams. The proposed model, based on rectangular geometry, is compared to a cubic unit cell model from the literature based on cylindrical struts, a tetrakaidecahedron model as well as a dodecahedron model (both based on either cylindrical of triangular struts). The predicted specific surface areas of the proposed model are of the same order of magnitude as the other model predictions from the literature. The relative percentage errors in the predicted values are at most equal to the relative percentage errors associated with the measured …