Download or read book Directionally Solidified Composites Known Also as in Situ Composites Or Directionally Solidified Eutectics written by NATIONAL MATERIALS ADVISORY BOARD (NAS-NAE) WASHINGTON D C. and published by . This book was released on 1973 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation of an in situ composite by means of appropriate directional solidification is a process with great potential for high-strength, high-temperature materials. An obvious primary application is for gas turbine blades, but non-structural applications also are possible and at least one of these is already a commercial product. The report, the results of a study by the ad hoc Committee on Directional Solidification of the National Materials Advisory Board, focuses on the potential of this new class of material, the problems to be faced in designing equipment using it, and the steps that should be taken to advance the science and technology of directionally solidified composited. (Modified author abstract).
Download or read book Directionally Solidified In situ Composites written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Structures and Materials Panel and published by . This book was released on 1974 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Specialists Meeting on Directionally Solidified In Situ Composites 38th Held in Washington D C on 23 24 April 1974 written by E. R. Thompson and published by . This book was released on 1974 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has long been recognized by the military aircraft community that increasing the temperature of turbine inlet gas in aircraft gas turbine engines offers attractive advantages in aircraft performance and economy. The high temperature characteristics of available materials of construction determine, to a large extent, the limits to which an engine can be designed. Thus the materials community has been engaged in trying to increase the high temperature capabilities of gas turbine materials. Directionally solidified eutectic alloys offer a new and very attractive approach toward increased metal operating temperatures. In contrast with the conventional precipitation hardened superalloys which tend to dissolve their strengthening precipitates at the very high temperatures and long times of operation, the eutectics should exhibit greater phase stability under these conditions. By proper alloy selection it has been found possible to precipitate very strong filaments or platelets of one metallurgical phase in a more ductile matrix of another and thus to achieve high temperature strengths far exceeding those of the best current superalloys. In essence the result is a metal matrix composite created 'in-situ' during directional solidification. The Specialists Meeting on In-situ Composites is reported on in this volume.
Download or read book Directionally Solidified in Situ Metal Matrix Composites written by G. Haour and published by . This book was released on 1976 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the present alloy screening program was to identify new eutectic superalloys suitable for the manufacture of directionally solidified turbine blades operating at up to 1150 C. In the course of this program, five eutectics not previously investigated have been found to meet the corresponding objectives of a melting point above 1200 C, a specific gravity below 9 g/cc and a reasonably low oxidation rate. The properties are comparable to those of the presently most advanced eutectic superalloys, such as Ni-2.5A1-19.7Nb-6Cr or Co20TaC-15Cr-8.5Ni-6W. Their oxidation rates, already comparable to that of Co- TaC, measured in the present study, could be further improved by compositional adjustments. These results were obtained on the basis of a screening of available phase diagrams for 107 alloy systems based on Ni, Co and Fe, from which 52 alloy systems were retained for further study. Twenty-eight simple ternary systems, either not previously evaluated or not described in sufficient detail, were examined experimentally by preparing several samples of compositions close to that determined by a semi-empirical graphical method as closest to the expected eutectic. As a result, 22 eutectics were identified and characterized in terms of melting temperature, microstructure and estimated density. Of these, 10 eutectics were found to meet the objectives of a melting point above 1200 C, a 'regular' microstructure presumably amenable to directional solidification and a density below 9 g/cc. They were therefore subjected to a systematic investigation of their oxidation resistance, leading to the identification of the 5 promising eutectics previously mentioned.
Download or read book Specialists Meeting on Directionally Solidified In Situ Composites written by E. R. Thompson and published by . This book was released on 1974 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directionally Solidified Composites Known Also as in Situ Composites Or Directionally Solidified Eutectics written by and published by National Academies. This book was released on 1973 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Specialists Meeting on written by E. R. Thompson and published by . This book was released on 1974 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Specialists meeting on directionally solidified in situ composites written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directionally Solidified In situ Composites written by E. R. Thompson and published by . This book was released on 1974 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directionally Solidified In situ Composites written by and published by . This book was released on 1974 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directionally Solidified Materials for High Temperature Service written by Malcolm McLean and published by . This book was released on 1983 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directionally Solidified In Situ Metal Matrix Composites written by G. Haour and published by . This book was released on 1976 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work constitutes Part II of an alloy screening program to identify new eutectics based on Ni, Co and Fe suitable for the manufacture of directionally solidified turbine blades operating at up to 1150 C. During this Part II, thirteen alloy systems, selected for screening during Part I, have been experimentally investigated, leading to the identification of three eutectics of potential interest: Co-Al-Cr, Co-Si-Nb and Co-Cr-Zr. As a result of the overall program, Part I and Part II, a total of 9 eutectics have thus been found to meet the objectives of a melting point above 1200 C, a specific gravity below 9 g/cc and a reasonably low parabolic oxidation rate. These eutectics thus have, before any development, an oxidation resistance comparable or superior to the chromium free gamma/gamma-delta eutectic superalloy Ni-2.55 A1-21.75 Nb (wt %). It is therefore expected that an alloy optimization program would improve their oxidation behavior, as compared to the gamma/gamma-delta alloy with 6% chromium, presently the most advanced eutectic of this class of materials.
Download or read book DIRECTIONALLY SOLIDIFIED IN SITU COMPOSITES PAPERS PRESENTED AT THE 38TH MEETING OF THE STRUCTURES AND MATERIALS PANEL OF AGARD written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directionally Solidified In situ Composites written by and published by . This book was released on 1974 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directionally Solidified In situ Composites written by E. Thompson and published by . This book was released on 1974 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directionally Solidified Eutectic Ceramics In Situ Composites for High Temperature Structural Applications written by and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eutectics are multiphase structures formed by the cooperative growth of two or more phases. Although the internal structure can vary widely, the development of continuous rods or plates in a matrix can be achieved and, within limits, can be controlled or "tailored" through directional solidification. The eutectic architecture of a continuous reinforcing phase within a higher volume phase or matrix, can be described as a naturally occurring in-situ composite. In-situ composites have been demonstrated to possess mechanical properties intermediate between monolithic materials and man-made composites and therefore may produce low cost high temperature structural material. Although several eutectic systems are currently being studied, two eutectics systems Al2O3/RE3Al5O12 (RE = Y, Er, Gd, Nd, Ho, Eu) and Al2O3/ZrO2(Y2O3) have been selected for the detailed examination of the advantages and the challenges associated with directional solidification. The Al2O3/Y3Al5Ol2 is comprised of two highly creep resistance oxides whereas Al2O3/ZrO2(Y2O3) combines a highly creep resistant material (Al2O3) with one having very poor creep properties (c-ZrO2(Y2O3)). To elucidate the potential of this family of materials for high temperature applications, parallel research efforts at different organizations are integrated. The ongoing research is closely coordinated with the efforts of Dr. S.C. Farmer at NASA Glenn Research Center (GRC), Prof. A.S. Argon at Massachusetts Institute of Technology (MIT) and Prof. E. Dickey at Penn State University (PSU). The efforts at MIT focuses on the high deformation characteristics of directionally solidified AL2O3/ZrO2(Y2O3). The efforts a PSU focuses on the correlation of interface structure and bonding from the atomistic length scale.
Download or read book Directionally solidified in situ composits papers presented at the 38th meeting of the Structures and Materials Panel in Washington D C 23 24 April 1974 written by and published by . This book was released on 1974 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
