Screen LibraryThe chemistry of non-sag tungsten /
Non-sag (NS) tungsten is a dispersion-strengthened microalloy with elemental potassium, which is contained as microscopic bubbles in the tungsten lattice. Under working conditions in an incandescent lamp the potassium is a gas under high pressure. These gas bubbles essentially prevent the recrystall...
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| Corporate Authors: | |
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| Group Author: | |
| Published: |
Pergamon,
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| Publisher Address: | Kidlington, Oxford, England ; Tarrytown, N.Y., U.S.A. : |
| Publication Dates: | 1995. |
| Literature type: | eBook |
| Language: | English |
| Edition: | First edition. |
| Subjects: | |
| Online Access: |
http://www.sciencedirect.com/science/book/9780080426761 |
| Summary: |
Non-sag (NS) tungsten is a dispersion-strengthened microalloy with elemental potassium, which is contained as microscopic bubbles in the tungsten lattice. Under working conditions in an incandescent lamp the potassium is a gas under high pressure. These gas bubbles essentially prevent the recrystallization of the tungsten wire and are responsible for the outstanding creep resistance of NS tungsten at the extremely high temperatures of a glowing lamp filament. More than 90% of NS tungsten is used for incandescent lamps. In addition, small amounts are used as defroster heating wires in automob |
| Item Description: | "Reprinted from: international journal of refractory metals & hard materials, vol. 14, (1-3)"--Title page verso. |
| Carrier Form: | 1 online resource (xi, 172 pages) : illustrations |
| Bibliography: | Includes bibliographical references and indexes. |
| ISBN: |
9781483287966 1483287963 |
| Index Number: | TN799 |
| CLC: | TN799.T9 |
| Contents: |
Front Cover; The Chemistry of Non-Sag Tungsten; Copyright Page; Table of Contents; Dedication; Foreword; Chapter 1. Aspects of Effective Doping and the Incorporation of Dopant; 1 INTRODUCTION; 2 BASIC MATERIALS SUITABLE FOR PRODUCING NS TUNGSTEN; 3 THE REDUCTION OF THE DOPED OXIDE TO METAL POWDER; 4 INTERMEDIATE AND END PRODUCTS IN THE INDUSTRIAL REDUCTION PROCESS; 5 THE EFFECT OF THE DOPANT FROM THE CHEMICAL POINT OF VIEW; 6 THE ROLE OF NITROGEN (NH3) IN THE PRODUCTION OF NS METAL FROM APT; 7 THE ROLE OF PHOSPHORUS (ASH3PO4) IN THE REDUCTION OF WO3 AND APT IN HYDROGEN. 5 PURIFICATION STEPS6 CONVERSION OF SODIUM TUNGSTATE TO AMMONIUM POLYTUNGSTATE; 7 AMMONIUM PARATUNGSTATE (APT)CRYSTALLIZATION; 8 AMMONIUM PARATUNGSTATE (APT); REFERENCES; Chapter 3. Effluent-Free Manufacture of Ammonium Paratungstate (APT) by Recycling the Byproducts; 1 INTRODUCTION; 2 SPECIAL ENVIRONMENTAL CONSIDERATIONS IN THE MANUFACTURE OF APT AND TUNGSTIC ACID; 3 ELECTRODIALYSISOFTHENa2W04 SOLUTION; 4 ENERGY CONSUMPTION OF THE ELECTRODIALYTIC RECOVERY OF NaOH; 5 KEY PARTS OF THE ELECTRODIALYZERS AND THEIR RELIABILITY. 6 COUPLING OF ELECTRODIALYTIC NaOH RECOVERY WITH SOLVENT EXTRACTION AND OTHER PROCESSES7 HYDROMETALLURGICAL PROCESSING OF TUNGSTEN SCRAP; 8 IMPLEMENTATION STAGES OF THE PROCESSES AND EQUIPMENT; 9 DEVELOPMENT POTENTIALS FOR THE APT MANUFACTURING PROCESSES; ACKNOWLEDGEMENTS; REFERENCES; Chapter 4. Crystallisation and Processing of Ammonium Paratungstate (APT); 1 CRYSTALLISATION OF AMMONIUM PARATUNGSTATE; 2 PROCESSING OF APT TO TUNGSTEN BLUE OXIDE; REFERENCES; Chapter 5. Chemistry of Tungsten Oxide Bronzes; 1 INTRODUCTION; 2 GENERAL CHARACTERIZATION OF OBs; 3 PREPARATION METHODS FOR OBs. 4 STRUCTURAL DESCRIPTION OF TOB6 THERMAL DECOMPOSITION OF TOBs; 7 ION EXCHANGE PROPERTIES OF TOB; 8 A(H)TOB-A DECOMPOSITION PRODUCT OF APT; 9 SURFACE CHEMICAL REACTIONS OF THE ATOB ON DOPING; 10 THE MORPHOLOGY OF TOB; REFERENCES; Chapter 6. The Crystal Chemistry of the Higher Tungsten Oxides; INTRODUCTION; TUNGSTEN TRIOXIDE AND THE TUNGSTATES; TUNGSTEN BRONZES WITH THE PEROVSKITE STRUCTURE; CRYSTALLOGRAPHIC SHEAR STRUCTURES; STRUCTURES CONTAINING PENTAGONAL BIPYRAMIDS; CRYSTALLOGRAPHIC SHEAR VERSUS PENTAGONAL BIPYRAMIDS; THE HEXAGONAL TUNGSTEN BRONZES AND RELATED STRUCTURES. |