DOCSLIB.ORG

Catalytic Converters (Background)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Catalytic Converters (Background) bulletin cover story Corning DuraTrap® GC gasoline particulate filter (foreground) and a Corning FLORA® low-mass substrate for catalytic converters (background). Smog begone! How development of ceramic automotive catalytic substrates and filters Credit: Corning Incorporated. eep in the heart of your car’s helped reduce Dexhaust system—withstanding temperatures of more than 1,800 degrees Fahrenheit and staying tough over hundreds of air pollution thousands of miles of bumpy roads—a highly engineered ceramic material is an important part of helping to prevent harmful emissions from escaping into the air you breathe. By keeping the air cleaner, these same ceramic products help save as many as 160,000 lives each year and help to prevent just By Douglas M. Beall and Willard A. Cutler as many cases of heart disease and asthma.1 From 1975 through today, light and heavy-duty vehicle emis- sions dropped by an astounding 99%. Ceramic-based mobile Ceramic-based mobile emissions control products have emissions control products prevented more than 4 billion tons of prevented billions of tons of hydrocarbons, nitrogen oxides, hydrocarbons, 4 billion tons of nitrogen oxides (NOx), and 40 bil- lion tons of carbon monoxide from entering the atmosphere. carbon monoxide, and particulates from entering the atmo- The clean-air movement brought economic benefits as well. sphere—and researchers continue to innovate to make these Emissions-related technologies represent about $37 billion in products even better. annual economic activity, with a significant portion of the indus- try involving ceramic-based components.2 Capsule summary A DIRTY PROBLEM CERAMIC SOLUTION INNOVATION AHEAD By the mid-1900s, health hazards associated In the 1970s, Corning scientists invented a Most emissions in a typical drive cycle are with poor air quality had come into stark view. substrate for catalytic convertors based on produced in the first minutes of operation, Governments set new federal air pollution cordierite and also a ceramic-based wall-flow so the remaining frontier of a zero-emission regulations that presented both a technologi- particulate filter for diesel engines. Nowadays, internal combustion vehicle is tackling this first cal challenge and business opportunity for ceramic substrates and filters are the keystone minute of operation. industry manufacturers. of mobile pollution control ecosystems. 24 www.ceramics.org | American Ceramic Society Bulletin, Vol. 99, No. 3 Innovations in ceramics will continue began its first attempt to legislate a solu- Control Act of 1965, and the Air Quality to be needed for at least the next couple tion with the Air Pollution Control Act Act of 1967 all lacked the teeth to make a of decades. Consumers throughout the of 1955, which focused on research and difference in the deadly problem. world, not only in areas with untreated information, leaving the states to devise But in 1970, sweeping new federal mobile pollution sources, are demanding ways to deal with polluters. A few states, regulations required clean-air compliance better air quality. Areas of focus that con- notably California, had a plan to combat from every segment of industry. The new tinue to drive ceramic innovations include the issue. Environmental Protection Agency (EPA) (1) Ensuring that real-world emissions The U.S. government made several was formed with the mandate to enforce are as low as emissions on the certifica- more attempts to regulate sources of air the regulations. tion test; pollution. However, the Clean Air Act of The Clean Air Act of 1970 estab- (2) Gaseous emission limits reduc- 1963, the Motor Vehicle Air Pollution lished air-quality standards that strictly ing, particularly NOx emissions, while supporting the reduction of greenhouse Clean Air Act of 1970 extreme benefits thanks to this legislation. gases; and For example, a 2011 EPA study2 estimated When it comes to clean air in the United (3) Reducing the last remaining bursts the central benefits exceed costs by a factor States, one of the most important pieces of of gaseous and particulate emissions of more than 30 to one, largely due to reduc- legislation that made it possible is the Clean tions in premature mortality associated with from internal combustions engines, the Air Act (CAA) of 1970. reductions in ambient particulate matter. emissions that occur during the first Prior to CAA 1970, there were a few federal minute or two of vehicle operation—an However, the gains in clean air made thanks acts involving air pollution.1 The first was the event that can happen several times dur- to CAA 1970 and its amendments may be Air Pollution Control Act of 1955, which pro- challenged in the future. The Trump admin- ing a drive with hybrid vehicles. vided funds for federal research on air pollu- istration has pursued the rollback of almost tion. This was followed by CAA 1963, which 100 environmental rules, 58 of which are now A growing dirty problem established a federal program within the U.S. completed. Of these completed rollbacks, 16 By the late-1940s, industrial activity in Public Health Service and authorized research involve air pollution and emissions rules.3 the United States had grown for nearly a into techniques for monitoring and control- ling air pollution. In 1967, the Air Quality Act Recent studies also show air quality improve- century. Little attention was paid to the ment is leveling off. A 2018 report4 by the consequences of smoke and pollutants was enacted to expand federal government activities, including conducting the first-ever U.S. PIRG Education Fund and Environment from coal-burning factories. Suburbs extensive ambient monitoring studies and America Research & Policy Center found were growing. More and more fami- stationary source inspections. 2018 had more days of pollution than each of lies could afford cars. With city traffic the previous five years, a finding supported crowding new highways, unprecedented However, CAA 1970 marked a major shift in by studies by the American Lung Association5 the federal government’s role in air pol- and Carnegie Mellon University.6 levels of harmful chemicals flowed into lution control by substantially expanding the air, especially in major population the government’s enforcement authority.1 References: centers—both in the U.S. and in other It authorized development of comprehen- 1United States Environmental Protection Agency. “Evolution developed countries. sive federal and state regulations to limit of the Clean Air Act.” Accessed 28 Feb. 2020. https:// www.epa.gov/clean-air-act-overview/evolution-clean- The health hazards associated with emissions from both stationary (industrial) air-act poor air quality came into stark global sources and mobile sources. In particular, it 2United States Environmental Protection Agency. “Benefits view in London in late 1952, when air- established four major regulatory programs and Costs of the Clean Air Act 1990-2020, the Second affecting stationary sources: Prospective Study.” Accessed 28 Feb. 2020. https://www. borne pollutants, mostly arising from the epa.gov/clean-air-act-overview/benefits-and-costs-clean- use of coal, mixed with fog to form a thick • National Ambient Air Quality Standards air-act-1990-2020-second-prospective-study blanket of smog over the city. Historical (NAAQS) 3N. Popovich, L. Albeck-Ripka, and K. Pierre-Louis (21 Dec. accounts vary on the details, but most • State Implementation Plans (SIPs) 2019). “95 environmental rules being rolled back under Trump,” The New York Times. https://www.nytimes.com/ agree between 4,000 and 6,000 people • New Source Performance Standards interactive/2019/climate/trump-environment-rollbacks. died over the course of five days from the (NSPS) html choking effects of the Great Smog.3,4 • National Emission Standards for Hazard- 4E. Ridlington, G. Weissman, and M. Folger (Winter 2020). The following year, New York City ous Air Pollutants (NESHAPs) “Trouble in the air: Millions of Americans breathed polluted air in 2018.” U.S. PIRG Education Fund. Accessed 28 Feb. was covered with a toxic mix of sulfur In 1977 and 1990, two sets of major amend- 2020. https://uspirgedfund.org/sites/pirg/files/reports/ dioxide and carbon monoxide that blan- ments were added to CAA 1970.1 The 1977 EnvironmentAmerica_TroubleintheAir_scrn.pdf keted the city. During one week, accord- amendments focused on ensuring attainment 5American Lung Association. “The state of the air 2019.” and maintenance of NAAQS by establishing Accessed 28 Feb. 2020. https://www.lung.org/our-initia- ing to reports, as many as 260 deaths tives/healthy-air/sota/key-findings/ major permit review requirements; the 1990 were attributed to the smog. More 6 amendments substantially increased the fed- K. Clay and N. Z. Muller (October 2019). “Recent deadly smog crises would hit both New increases in air pollution: Evidence and implications for York and London again over the follow- eral government’s authority and responsibility. mortality.” NBER, Working Paper No. 26381. https://www. nber.org/papers/w26381 n ing decades.5 To date, several in-depth benefit-cost analy- With the public health effects of air ses of the CAA Amendments performed by pollution now beyond dispute, the U.S. the Environmental Protection Agency all show American Ceramic Society Bulletin, Vol. 99, No.3 | www.ceramics.org 25 Smog begone! How development of ceramic automotive catalytic substrates and . a) b) c) d) Schematic of laboratory scale production Figure 1. Numerous pathways to fabricating porous ceramic substrates were tried before settling on extruded honeycombs. (a) Alternate layers of flat and crimped paper infused with glass- Credit: Beall and Cutler ceramic (CERCOR material); (b) layers of cordierite glass-ceramic sheets with small “nubbins” to increase the surface area and permit exhaust flow; (c) open, layered structure similar to ribbon candy formed by buckling a hot glass stream and later ceraming the part; and (d) glass tubing fused together, then ceramed, looking like a packet of hollow cigarettes.
Load more

Recommended publications
  • Simultaneous PAN Carbonization and Ceramic Sintering for Fabricating Carbon Fiber-Ceramic Composite Heaters
    applied sciences Article Simultaneous PAN Carbonization and Ceramic Sintering for Fabricating Carbon Fiber-Ceramic Composite Heaters Daiqi Li 1,2, Bin Tang 1,2 , Xi Lu 1, Quanxiang Li 1, Wu Chen 2, Xiongwei Dong 2, Jinfeng Wang 1,2,* and Xungai Wang 1,2,* 1 Deakin University, Institute for Frontier Materials, Geelong/Melbourne, Victoria 3216, Australia; [email protected] (D.L.); [email protected] (B.T.); [email protected] (X.L.); [email protected] (Q.L.) 2 Wuhan Textile University, Joint Laboratory for Advanced Textile Processing and Clean Production, Wuhan 430073, China; [email protected] (W.C.); [email protected] (X.D.) * Correspondence: [email protected] (X.W.); [email protected] (J.W.); Tel.: +61-3-5227-2012 (J.W.) Received: 15 October 2019; Accepted: 14 November 2019; Published: 17 November 2019 Abstract: In this study, a single firing was used to convert stabilized polyacrylonitrile (PAN) fibers and ceramic forming materials (kaolin, feldspar, and quartz) into carbon fiber/ceramic composites. For the first time, PAN carbonization and ceramic sintering were achieved simultaneously in one thermal cycle and the microscopic morphologies and physical features of the obtained carbon fiber/ceramic composites were characterized in detail. The obtained carbon fiber/ceramic composite showed comparable flexural strength as commercial ceramic tiles. Meanwhile, the composite showed exceptional electro-thermal performance based on the electro-thermal performance of the carbonized PAN fibers, which could reach 108 °C after 15 s, 204 °C after 90 s, and 292 °C after 450 s at 5 V (2.6 A), thereby making the ceramic composite a good candidate as an indoor climate control heater, defogger device, kettle, and other heating element.
    [Show full text]
  • Ceramic Carbides: the Tough Guys of the Materials World
    Ceramic Carbides: The Tough Guys of the Materials World by Paul Everitt and Ian Doggett, Technical Specialists, Goodfellow Ceramic and Glass Division c/o Goodfellow Corporation, Coraopolis, Pa. Silicon carbide (SiC) and boron carbide (B4C) are among the world’s hardest known materials and are used in a variety of demanding industrial applications, from blasting-equipment nozzles to space-based mirrors. But there is more to these “tough guys” of the materials world than hardness alone—these two ceramic carbides have a profile of properties that are valued in a wide range of applications and are worthy of consideration for new research and product design projects. Silicon Carbide Use of this high-density, high-strength material has evolved from mainly high-temperature applications to a host of engineering applications. Silicon carbide is characterized by: • High thermal conductivity • Low thermal expansion coefficient • Outstanding thermal shock resistance • Extreme hardness FIGURE 1: • Semiconductor properties Typical properties of silicon carbide • A refractive index greater than diamond (hot-pressed sheet) Chemical Resistance Although many people are familiar with the Acids, concentrated Good Acids, dilute Good general attributes of this advanced ceramic Alkalis Good-Poor (see Figure 1), an important and frequently Halogens Good-Poor overlooked consideration is that the properties Metals Fair of silicon carbide can be altered by varying the Electrical Properties final compaction method. These alterations can Dielectric constant 40 provide knowledgeable engineers with small Volume resistivity at 25°C (Ohm-cm) 103-105 adjustments in performance that can potentially make a significant difference in the functionality Mechanical Properties of a finished component.
    [Show full text]
  • Introduction to Metal-Ceramic Technology Third Edition
    Introduction to Metal-Ceramic Technology Third Edition Naylor_FM.indd 1 10/20/17 8:57 AM IntroductionMetal-Ceramic to Technology Third Edition W. Patrick Naylor, DDS, MPH, MS Adjunct Professor of Restorative Dentistry Loma Linda University School of Dentistry Loma Linda, California With contributions by Charles J. Goodacre, DDS, MSD Distinguished Professor of Restorative Dentistry Loma Linda University School of Dentistry Loma Linda, California Satoshi Sakamoto, MDT Master Dental Technician Loma Linda University School of Dentistry Loma Linda, California Berlin, Barcelona, Chicago, Istanbul, London, Milan, Moscow, New Delhi, Paris, Prague, Sao Paulo, Seoul, Singapore, Tokyo, Warsaw Naylor_FM.indd 3 10/20/17 8:58 AM Dedications To my dear wife, Penelope, for her skillful reviewing and patience over the many months devoted to the production of this third edition. And to the memory of my mentor, teacher, and friend, Dr Ralph W. Phillips. As an expert of international renown, his contributions to dental materials science and dentistry in general are immeasurable. This is a small tribute to a man who left an indelible mark on the dental profession. Library of Congress Cataloging-in-Publication Data Names: Naylor, W. Patrick, author. Title: Introduction to metal-ceramic technology / W. Patrick Naylor. Description: Third edition. | Hanover Park, IL : Quintessence Publishing Co, Inc, [2017] | Includes bibliographical references and index. Identifiers: LCCN 2017031693 (print) | LCCN 2017034109 (ebook) | ISBN 9780867157536 (ebook) | ISBN 9780867157529 (hardcover) Subjects: | MESH: Metal Ceramic Alloys | Dental Porcelain | Technology, Dental--methods Classification: LCC RK653.5 (ebook) | LCC RK653.5 (print) | NLM WU 180 |DDC 617.6/95--dc23 LC record available at https://lccn.loc.gov/2017031693 97% © 2018 Quintessence Publishing Co, Inc Quintessence Publishing Co, Inc 4350 Chandler Drive Hanover Park, IL 60133 www.quintpub.com 5 4 3 2 1 All rights reserved.
    [Show full text]
  • Ceramic Engineering Building
    CERAMIC ENGINEERING BUILDING UNIVERSITY OF ILLINOIS URBANA CHAMPAIGN, ILLINOIS Description of the Building and Program of Dedication, December 6 unci 7, 1916 THE TRUSTEES THE PRESIDENT AND THE FACULTY OF THIS UNIVERSITY OF ILLINOIS CORDIALLY INVITE YOU TO ATTEND THE DEDICATION OF THE CERAMIC ENGINEERING BUDUDING ON WEDNESDAY AND THURSDAY DECEMBER SIXTH AND SEVENTH NINETEEN HUNDRED SIXTEEN URBANA. ILLINOIS CERAMIC ENGINEERING BUILDING UNIVERSITY OF ILLINOIS URBANA - - CHAMPAIGN ILLINOIS DESCRIPTION OF BUILDING AND PROGRAM OF DEDICATION DECEMBER 6 AND 7, 1916 PROGRAM FOR THE DEDICATION OP THE CERAMIC ENGINEERING BUILDING OF THE UNIVERSITY OF ILLINOIS December 6 and 7> 1916 WEDNESDAY, DECEMBER 6 1.30 p. M. In the office of the Department of Ceramic Engineering, Room 203 Ceramic Engineering Building Meeting of the Advisory Board of the Department of Ceramic Engineering: F. W. BUTTERWORTH, Chairman, Danville A. W. GATES Monmouth W. D. GATES Chicago J. W. STIPES Champaign EBEN RODGERS Alton 2.30-4.30 p, M. At the Ceramic Engineering Building Opportunity will be given to all friends of the University to inspect the new building and its laboratories. INTRODUCTORY SESSION 8 P.M. At the University Auditorium DR. EDMUND J. JAMBS, President of the University, presiding. Brief Organ Recital: Guilnant, Grand Chorus in D Lemare, Andantino in D-Flat Faulkes, Nocturne in A-Flat Erb, Triumphal March in D-Flat J. LAWRENCE ERB, Director of the Uni­ versity School of Music and University Organist. PROGRAM —CONTINUED Address: The Ceramic Resources of America. DR. S. W. STRATTON, Director of the Na­ tional Bureau of Standards, Washington, D. C. I Address: Science as an Agency in the Develop­ ment of the Portland Cement Industries, MR.
    [Show full text]
  • CERAMICS I and II GRADES 9-12 EWING PUBLIC SCHOOLS 2099 Pennington Road Ewing, NJ 08618 Board Approval Date: August 29, 2016 M
    CERAMICS I AND II GRADES 9-12 EWING PUBLIC SCHOOLS 2099 Pennington Road Ewing, NJ 08618 Board Approval Date: August 29, 2016 Michael Nitti Produced by: James Woidill, Supervisor Superintendent In accordance with The Ewing Public Schools’ Policy 2230, Course Guides, this curriculum has been reviewed and found to be in compliance with all policies and all affirmative action criteria. Table of Contents Page Course Description and Rationale 1 Scope and Sequence of Essential Learning: Ceramics I: Unit 1: Introduction to Ceramics/History 2 Unit 2: Procedures, Properties and Vocabulary of Clay 5 Unit 3: Hand-Building Techniques and Glazing 8 Unit 4: Refining, Finishing and Glazing 11 Unit 5: The Firing Process 14 Ceramics II: Unit 6: Hand-Building/Throwing Techniques 17 Unit 7: Exploring the Creative Process 20 Unit 8: Art in a Historical and Cultural Context 23 Unit 9: Contemporary Ceramists/Careers in Ceramics 26 Ceramics I and II Worksheet 29 Ceramic Critique Form 30 Art Criticism Scoring Guide 31 Glossary of Ceramic Terms 33 1 Course Description and Rationale Ceramics I: Ceramics I is an introduction to working with clay and understanding the ceramic process from start to finish. The relationship between form and function will be critically examined as students learn basic hand building and techniques. The direction of their work will evolve as they reflect on their changing definitions of art. Ceramics I is designed for students who have never had ceramics at the high school level. Students are taught how to build pottery by use of pinch, coil and slab methods of construction.
    [Show full text]
  • Silicon Carbide: Synthesis and Properties 16
    Silicon Carbide: Synthesis and Properties 361 16X Silicon Carbide: Synthesis and Properties Houyem Abderrazak1 and Emna Selmane Bel Hadj Hmida2 1 Institut National de Recherche et d’Analyse Physico-Chimique, Pole Technologique Sidi Thabet, 2020, Tunisia 2 Institut Préparatoire Aux Etudes d’Ingénieurs El Manar 2092, Tunisia 1. Introduction Silicon carbide is an important non-oxide ceramic which has diverse industrial applications. In fact, it has exclusive properties such as high hardness and strength, chemical and thermal stability, high melting point, oxidation resistance, high erosion resistance, etc. All of these qualities make SiC a perfect candidate for high power, high temperature electronic devices as well as abrasion and cutting applications. Quite a lot of works were reported on SiC synthesis since the manufacturing process initiated by Acheson in 1892. In this chapter, a brief summary is given for the different SiC crystal structures and the most common encountered polytypes will be cited. We focus then on the various fabrication routes of SiC starting from the traditional Acheson process which led to a large extent into commercialization of silicon carbide. This process is based on a conventional carbothermal reduction method for the synthesis of SiC powders. Nevertheless, this process involves numerous steps, has an excessive demand for energy and provides rather poor quality materials. Several alternative methods have been previously reported for the SiC production. An overview of the most common used methods for SiC elaboration such as physical vapour deposition (PVT), chemical vapour deposition (CVD), sol-gel, liquid phase sintering (LPS) or mechanical alloying (MA) will be detailed. The resulting mechanical, structural and electrical properties of the fabricated SiC will be discussed as a function of the synthesis methods.
    [Show full text]
  • Ceramic Engineering at Iowa State Lillian Goodrow Iowa State College
    Volume 9 Article 5 Number 6 The Iowa Homemaker vol.9, no.6 1929 Ceramic Engineering at Iowa State Lillian Goodrow Iowa State College Follow this and additional works at: http://lib.dr.iastate.edu/homemaker Part of the Home Economics Commons Recommended Citation Goodrow, Lillian (1929) "Ceramic Engineering at Iowa State," The Iowa Homemaker: Vol. 9 : No. 6 , Article 5. Available at: http://lib.dr.iastate.edu/homemaker/vol9/iss6/5 This Article is brought to you for free and open access by the Student Publications at Iowa State University Digital Repository. It has been accepted for inclusion in The oI wa Homemaker by an authorized editor of Iowa State University Digital Repository. For more information, please contact [email protected]. THE IOWA HOMEMAKER 3 Ceramic Engineering at Iowa State by Lillian Goodrow ERAMIC ENGINEERING is pri­ craft schools, and the courses offered can Youth; " and Carl Schiller, who is C marily a course for engineers, and here are exactly right for that. the directing chef of the P ennsylvania Railroad, will speak on ''The Planning study in it leads to a bachelor of Research work from Iowa clays has science degree. The ceramic technology and Directing of Meals.'' Miss Betty advanced rapidly in the last few years. Eckhart, of the West Virginia Extension course prepares men for silicate indus­ There are now on the markets products tries, which include the manufacture of Department, will have complete charge of made from ''Ames Pottery.'' It has the recreation program. heavy products (bricks, tiles and terra not only received recognition, but there cotta), tableware, glassware, enamel, Mass meetings will be held every even­ are consignments of pottery all over the ing.
    [Show full text]
  • Patent Law Fundamentals for Innovators in the Ceramic and Glass Industry
    atents are an important class of Passet for any company. For a start- up company, its patent portfolio may be its most important asset. Despite their impor- tance, patents and the surrounding law may Patent law not be well understood by researchers and management. Therefore, they risk mak- ing decisions or taking actions that could fundamentals negatively impact their ability to pursue and obtain patent protection for their inventions. The best way for a company to avoid costly for innovators in mistakes at a critical juncture is to become better informed about the patent process and work closely with a patent attorney at all the ceramic and stages of an invention. Because of the significant changes wrought by the recent America Invents Act (AIA), it is more important than ever glass industry to take proactive, forward-looking measures to position inno- vations properly for the patent process. This article sets forth some fundamental principles regarding patents and the require- ments for obtaining patents, describes the types of patents relevant to the ceramic and glass industry, and briefly discusses By Steve Ritchey the significant changes in patent law from the AIA. What is a patent? In general, a patent is a grant of some privilege, property, or authority made by a government to one or more persons. In the United States, Article I, Section 8, Clause 8 of the Constitution provides Congress the power to “promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their Part one of a two-part series presents the importance of respective Writings and Discoveries.” patents to companies and the requirements that must be met The patent and copyright clause of the Constitution was before patents are granted.
    [Show full text]
  • Review on Intermetallic and Ceramic Nanoparticle Coatings for Application in High Temperatures
    Volume 3, Issue 5, May – 2018 International Journal of Innovative Science and Research Technology ISSN No:-2456-2165 Review on Intermetallic and Ceramic Nanoparticle Coatings for Application in High Temperatures Gaurav Siwal, Mechanical Engineering Department, Dronacharya Group of Institutions, Greater Noida, U.P. Member of ISTE Abstract:- As compared to material with ordinary grain decide the electrical, optical and magnetic properties. As the size, Nano Materials have special properties. The Idea is to particle is reduced in size these energy bands get thin and study the properties and coating techniques for ceramic sharp. For Nano sized particles the electrons get scattered on and intermetallic nanostructure which could be deposited the surface and resistivity increases. as a protective layer. Some methods include Inert gas condensation, PVD, CVD, Sol-gel, Electrochemical D. Optical property deposition, thermal spray, and pulsed electro-spark When the size of a crystal becomes smaller and deposition. The composition of the material and comparable to wavelength of visible light, nanoparticles microstructure can be controlled using different electrodes, partially transmit the light which results in change of color. For and adjusting the parameters of the setup. Nano Material example Au nanoparticle of size between 30 - 500nm appears coatings on surface can modify chemical, mechanical and blue to red in color from larger to smaller size. electronic properties. It can also improve high-temperature corrosion and corrosive wear resistance. These E. Magnetic Property modification techniques can have various applications in The total magnetic moment is the property which turbine blades, engine parts for petrochemical, aerospace depends upon number of atoms; it depends upon the size of the and electronic device industries.
    [Show full text]
  • Advanced Ceramic Powders —
    Advanced Ceramic Powders — 1 High Quality Partnerships — Welcome to Höganäs Our advanced ceramic powder solutions Our extensive portfolio includes the following material groups: We are a renowned manufacturer of high-quality ceramic • Boron (amorphous and crystalline) powders for a diverse range of applications. We offer one of the • Borides, such as TiB2, ZrB2 and LaB6 most extensive material portfolios in non-oxide ceramic powders, • Carbides, such as B C, SiC and TiC Expertise, Quality and 4 specializing in boron, boride, carbide and nitride powders. Our • Nitrides, such as Si3N4, AlN, BN, TiN high-quality products are utilized in applications such as clean • Oxides, Silicon & Silicides energy technologies, technical ceramics, thermal management, • Special carbides, such as Cr C , VC, Mo C Care for Customers 3 2 2 and pyrotechnics. and WTiC, for the hard metal industry Our business is defined by our customer focus and customer partnerships, which have made us one of the most Our distribution network — successful ceramic powder manufacturers worldwide. Our Throughout the world, Höganäs is represented by its sales experts continuously provide customers with technical support offices and agencies. We offer regional technical support and as well as with a wealth of material knowledge. short response times. This is the key in providing an individual- Whenever ideas are to be turned into successful products or Together, we will continue to invest and develop state-of- In addition to our vast portfolio of standard grades, we also ized, highly flexible service. applications, the first step is to find the right material supplier. the-art powders and processes for a myriad of applications.
    [Show full text]
  • Silicon Nitride, a Close to Ideal Ceramic Material for Medical Application
    ceramics Review Silicon Nitride, a Close to Ideal Ceramic Material for Medical Application Robert B. Heimann Am Stadtpark 2A, D-02826 Görlitz, Germany; [email protected]; Tel.: +49-3581-667851 Abstract: This topical review describes the salient results of recent research on silicon nitride, a ceramic material with unique properties. The outcome of this ongoing research strongly encourages the use of monolithic silicon nitride and coatings as contemporary and future biomaterial for a variety of medical applications. Crystallographic structure, the synthesis and processing of monolithic structures and coatings, as well as examples of their medical applications that relate to spinal, orthopedic and dental implants, bone grafts and scaffolds, platforms for intelligent synthetic neural circuits, antibacterial and antiviral particles and coatings, optical biosensors, and nano-photonic waveguides for sophisticated medical diagnostic devices are all covered in the research reviewed herein. The examples provided convincingly show that silicon nitride is destined to become a leader to replace titanium and other entrenched biomaterials in many fields of medicine. Keywords: silicon nitride; structure; properties; processing; coatings; spinal implants; arthroplastic implants; bone scaffolds; dental implants; neural circuits; biosensors; medical diagnostics Citation: Heimann, R.B. Silicon 1. Introduction Nitride, a Close to Ideal Ceramic Material for Medical Application. Today, the research and development of metallic, ceramic, polymeric and composite Ceramics 2021, 4, 208–223. biomaterials have progressed to a high level of involvement and sophistication. This is https://doi.org/10.3390/ related to the fact that an ever-increasing part of the world population is in need of the repair ceramics4020016 or replacement of dysfunctional or damaged parts of the body, such as dental roots and teeth, alveolar ridge augmentation, intraocular lenses, heart pacemakers, cochlear implants, Academic Editors: Stuart Hampshire and hip and knee endoprostheses [1].
    [Show full text]
  • Enabling Science for Advanced Ceramic Membrane Electrolyzers
    Proceedings of the 2002 U.S. DOE Hydrogen Program Review NREL/CP-610-32405 Enabling Science for Advanced Ceramic Membrane Electrolyzers Fernando H. Garzon, R. Mukundan, and Eric L. Brosha MST-11 - Electronic and Electrochemical Materials and Devices Group Los Alamos Natiional Laboratory, Los Alamos New Mexico 87545 Introduction Efficient and economical electrolysis of water to hydrogen and oxygen gases is of great importance to renewable hydrogen energy programs. Combined fuel cell/electrolyzer systems offer the potential for efficient energy storage and conversion. Unfortunately, low-cost and low- maintenance electrolyzer technologies are not commercially available. Current alkaline and polymer membrane based electrolysis systems suffer from the following disadvantages: • The hydrogen product gas is saturated with water vapor; the gas must be dried before the hydrogen can be stored in a hydride bed. • Both technologies require high loadings of precious metal catalysts to reduce the overpotential losses. • Neither technology is amenable to high-pressure operation. It is very difficult to pressurize wet alkaline electrolyte cells. Polymer membrane cells allow high crossover rates of gases across the membranes at elevated pressures. • Long-term stability and contamination is a problem with both alkaline and PEM electrolysis electrolytes. Alkaline electrolytes adsorb carbon dioxide readily and form carbonates. Polymer membrane systems must use very pure de-ionized water or they will accumulate cations that displace protons and increase the cell resistance over time. A promising alternative to liquid and polymer membrane electrolytes is a proton conducting ceramic solid electrolyte technology. This technology is intrinsically different than zirconia-based oxygen ion electrolyzers in that the transported (separated) species is hydrogen rather than oxygen.
    [Show full text]