Author: L. A. McClaine
Publisher:
ISBN:
Category : Electric conductivity
Languages : en
Pages : 240
Book Description
Work presented includes: preparation of borides and carbides; low temperature heat capacity measurements on HfB2, HfC and hafnium metal; estimation of entropies at 298K for refractory diborides, nitrides, carbides, and oxides from high temperature heat content data; current status of heats of formation of the borides and carbides from oxygen and fluorine bomb calorimetry; and studies proving the feasibility of the matrix isolation technique for spectroscopy of high temperature molecules through studies on the Lithium halides. Status of electron diffraction, equilibria, and heat of solution studies of the hafnium and zirconium halides is presented. Kinetic studies completed on the oxidation and fluorination of the hafnium and zirconium carbides and diborides are presented in detail. From ac and dc electrical conductivity studies on tetragonal ZrO2, a model of the defect structure is devised and oxygen diffusion in ZrO2 is calculated. (Author).
Thermodynamic and Kinetic Studies for a Refractory Materials Program
Author: L. A. McClaine
Publisher:
ISBN:
Category : Electric conductivity
Languages : en
Pages : 240
Book Description
Work presented includes: preparation of borides and carbides; low temperature heat capacity measurements on HfB2, HfC and hafnium metal; estimation of entropies at 298K for refractory diborides, nitrides, carbides, and oxides from high temperature heat content data; current status of heats of formation of the borides and carbides from oxygen and fluorine bomb calorimetry; and studies proving the feasibility of the matrix isolation technique for spectroscopy of high temperature molecules through studies on the Lithium halides. Status of electron diffraction, equilibria, and heat of solution studies of the hafnium and zirconium halides is presented. Kinetic studies completed on the oxidation and fluorination of the hafnium and zirconium carbides and diborides are presented in detail. From ac and dc electrical conductivity studies on tetragonal ZrO2, a model of the defect structure is devised and oxygen diffusion in ZrO2 is calculated. (Author).
Publisher:
ISBN:
Category : Electric conductivity
Languages : en
Pages : 240
Book Description
Work presented includes: preparation of borides and carbides; low temperature heat capacity measurements on HfB2, HfC and hafnium metal; estimation of entropies at 298K for refractory diborides, nitrides, carbides, and oxides from high temperature heat content data; current status of heats of formation of the borides and carbides from oxygen and fluorine bomb calorimetry; and studies proving the feasibility of the matrix isolation technique for spectroscopy of high temperature molecules through studies on the Lithium halides. Status of electron diffraction, equilibria, and heat of solution studies of the hafnium and zirconium halides is presented. Kinetic studies completed on the oxidation and fluorination of the hafnium and zirconium carbides and diborides are presented in detail. From ac and dc electrical conductivity studies on tetragonal ZrO2, a model of the defect structure is devised and oxygen diffusion in ZrO2 is calculated. (Author).
Thermodynamic and Kinetic Studies for a Refractory Materials Program
Author: L. A. McClaine
Publisher:
ISBN:
Category : Borides
Languages : en
Pages : 85
Book Description
Summary of an integrated program of studies developed to provide thermodynamic and kinetic knowledg needed to describe the chemical behavior of zirconium and hafnium carbides and borides at temperatures to 3000K and in atmospheres of O2, O2 + H2O, Cl2, HF, F2 H, CO, NH, A D N2. Both internal and subcontracted efforts are used which can (1) provide, through calorimetric measurements, additional thermodynamic data needed for the tabula ion of free energy functions of the zirconium and hafnium carbides and borides; (2) identify, by mass spectrometric means, gaseous species formed on vaporization of these carbides and borides and on their interaction with the several atmospheres; (3) provide thermodynamic data for important gaseous species through electron diffraction techniques, matrix isolation spectroscopy, and equilibria studies; and (4) develop the kinetic of the reactions of the carbides and borides with the various tmospheres throug s udies of the over-all rates of reactions and mass transport mechanisms. The preparation and characterization of macrocrystalline, high purity ZrB2 and ZrC are described. Low temperature heat capacity data for ZrB2 and heat content dat for ZrB2, ZrC, and HfB2 are presented. Results of a study of the vaporization of ZrB2 are reported.
Publisher:
ISBN:
Category : Borides
Languages : en
Pages : 85
Book Description
Summary of an integrated program of studies developed to provide thermodynamic and kinetic knowledg needed to describe the chemical behavior of zirconium and hafnium carbides and borides at temperatures to 3000K and in atmospheres of O2, O2 + H2O, Cl2, HF, F2 H, CO, NH, A D N2. Both internal and subcontracted efforts are used which can (1) provide, through calorimetric measurements, additional thermodynamic data needed for the tabula ion of free energy functions of the zirconium and hafnium carbides and borides; (2) identify, by mass spectrometric means, gaseous species formed on vaporization of these carbides and borides and on their interaction with the several atmospheres; (3) provide thermodynamic data for important gaseous species through electron diffraction techniques, matrix isolation spectroscopy, and equilibria studies; and (4) develop the kinetic of the reactions of the carbides and borides with the various tmospheres throug s udies of the over-all rates of reactions and mass transport mechanisms. The preparation and characterization of macrocrystalline, high purity ZrB2 and ZrC are described. Low temperature heat capacity data for ZrB2 and heat content dat for ZrB2, ZrC, and HfB2 are presented. Results of a study of the vaporization of ZrB2 are reported.
Some Kinetic and Thermodynamic Properties of the Refractory Metal Borides and Nitrides
Thermodynamic and Kinetic Studies of Borides and Other Refractory Materials at High Temperatures
Author: John L. Margrave
Publisher:
ISBN:
Category :
Languages : en
Pages : 41
Book Description
The reactions of elementary fluorine with several refractory elements (B, C, Si, Zr and Ir) and with several refractory compounds (TiC, TiB2, WC and W2B5) have been quantitatively observed and rate equations derived. The products of fluorination have isolated and studied to provide further information. For example, solid CF(x), the reaction product between graphite and F2 at low temperatures, has been thermally decomposed and the products characterized by gas chromatography and mass spectrometry. The high temperature drop calorimeter has been remodeled and is now capable of operation at temperatures up to 2000 K with the samples being contained in a refractory metal capsule (Ir, Ta or Mo) and heated inductively. Measurements up to the highest temperatures on the easily oxidized borides and carbides have not yet been made because of problems in obtaining capsules which can be tightly sealed. Several designs have been investigated. With a Pt-Rh alloy, one can approach 1500 C and several studies have been carried out. Gold capsules are being used for collection of data up to 1000 C and the measurements will be extended when the capsules are available. Fluorine bomb calorimetry is being applied for determination of heat of formation of refractory borides and oxides. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 41
Book Description
The reactions of elementary fluorine with several refractory elements (B, C, Si, Zr and Ir) and with several refractory compounds (TiC, TiB2, WC and W2B5) have been quantitatively observed and rate equations derived. The products of fluorination have isolated and studied to provide further information. For example, solid CF(x), the reaction product between graphite and F2 at low temperatures, has been thermally decomposed and the products characterized by gas chromatography and mass spectrometry. The high temperature drop calorimeter has been remodeled and is now capable of operation at temperatures up to 2000 K with the samples being contained in a refractory metal capsule (Ir, Ta or Mo) and heated inductively. Measurements up to the highest temperatures on the easily oxidized borides and carbides have not yet been made because of problems in obtaining capsules which can be tightly sealed. Several designs have been investigated. With a Pt-Rh alloy, one can approach 1500 C and several studies have been carried out. Gold capsules are being used for collection of data up to 1000 C and the measurements will be extended when the capsules are available. Fluorine bomb calorimetry is being applied for determination of heat of formation of refractory borides and oxides. (Author).
Some Physical, Mechanical, and Thermodynamic Properties of Transition Metal Refractory Carbides
Author: Jean E. Senkin
Publisher:
ISBN:
Category : Bibliography
Languages : en
Pages : 204
Book Description
Publisher:
ISBN:
Category : Bibliography
Languages : en
Pages : 204
Book Description
Technical Publications Announcements with Indexes
Author: United States. National Aeronautics and Space Administration
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1318
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1318
Book Description
A Review of the Air Force Materials Research and Development Program
Author: Air Force Materials Laboratory (U.S.)
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 294
Book Description
Technical reports published by the Air Force Materials Laboratoy during the period 1 July 1962 - 30 June 1963 are abstracted herein. Reports on reseqrch conducted by the Air Force Materials Laboratory personnel as well as that conducted on contract are included. These reports cover basic and applied research in the materials area being conducted by the Metals and Ceramics Division, Non-metallic Materials Division, Materials Physics Division, Manufacturing Technology Division, and Materials Applications Division of the Air Force Materials Laboratory.
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 294
Book Description
Technical reports published by the Air Force Materials Laboratoy during the period 1 July 1962 - 30 June 1963 are abstracted herein. Reports on reseqrch conducted by the Air Force Materials Laboratory personnel as well as that conducted on contract are included. These reports cover basic and applied research in the materials area being conducted by the Metals and Ceramics Division, Non-metallic Materials Division, Materials Physics Division, Manufacturing Technology Division, and Materials Applications Division of the Air Force Materials Laboratory.
U.S. Government Research Reports
A Review of the Air Force Materials Research and Development Program
Author: United States. Wright Air Development Division
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 308
Book Description
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 308
Book Description
Discussion of Theoretical Studies
Author: Harold L. Schick
Publisher: Elsevier
ISBN: 1483273059
Category : Science
Languages : en
Pages : 685
Book Description
Thermodynamics of Certain Refractory Compounds, Volume I: Discussion of Theoretical Studies provides information pertinent to thermodynamics as a significant theoretical tool for predicting the chemical and physical behavior of materials under diverse environmental conditions. This book presents a summary of the methods used to analyze thermodynamic data. Organized into six chapters, this volume begins with an overview of the thermodynamic properties that have been obtained for a selected group of refractory compounds in the range from 0° to 6000°K. This text then examines the class of compounds, including the borides, oxides, carbides, and nitrides of some elements in groups IIA, IIIB, IVB, VB, VIB, VIIB, and VIII as well as some elements from the rare-earth and actinide series. Other chapters consider the need for standardization in methods of obtaining and presenting thermodynamic data. The final chapter deals with the recommendations for the advancement of work. This book is a valuable resource for scientists and engineers.
Publisher: Elsevier
ISBN: 1483273059
Category : Science
Languages : en
Pages : 685
Book Description
Thermodynamics of Certain Refractory Compounds, Volume I: Discussion of Theoretical Studies provides information pertinent to thermodynamics as a significant theoretical tool for predicting the chemical and physical behavior of materials under diverse environmental conditions. This book presents a summary of the methods used to analyze thermodynamic data. Organized into six chapters, this volume begins with an overview of the thermodynamic properties that have been obtained for a selected group of refractory compounds in the range from 0° to 6000°K. This text then examines the class of compounds, including the borides, oxides, carbides, and nitrides of some elements in groups IIA, IIIB, IVB, VB, VIB, VIIB, and VIII as well as some elements from the rare-earth and actinide series. Other chapters consider the need for standardization in methods of obtaining and presenting thermodynamic data. The final chapter deals with the recommendations for the advancement of work. This book is a valuable resource for scientists and engineers.