Download or read book Development and evaluation of die and container materials written by Battelle Memorial Institute. Columbus Laboratories and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Evaluation of Die and Container Materials written by R. R. Willis and published by . This book was released on 1978 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Evaluation of Die and Container Materials written by Battelle Memorial Institute. Columbus Laboratories and published by . This book was released on 1979 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Evaluation of Die and Container Materials written by Battelle Memorial Institute. Columbus Laboratories and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and evaluation of die and container materials written by Battelle Memorial Institute. Columbus Laboratories and published by . This book was released on 1978 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and evaluation of die and container materials written by Battelle Memorial Institute. Columbus Laboratories and published by . This book was released on 1978 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Evaluation of Die and Container Materials written by Battelle Memorial Institute. Columbus Laboratories and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Evaluation of Die and Container Materials written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: X = 0.75?' (a silicon aluminum oxynitride) and Sibeon (silicon beryllium oxynitride) are promising die materials. In sessile drop tests in contact with molten silicon, beryllium contamination was

Download or read book Development and Evaluation of Die and Container Materials Final Report written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Specific compositions of high purity silicon aluminum oxynitride (Sialon) and silicon beryllium oxynitride (Sibeon) solid solutions are shown to be promising refractory materials for handling and manipulating solar grade silicon into silicon ribbon. Well controlled processing schedules were developed for fabricating high purity Sialon and Sibeon materials. Essentially the impurity content of the hot pressed ceramics was due only to impurities from the original starting powders. A ceramic shaping die was successfully formed by diamond machining of a hot pressed blank. Projected manufacturing cost estimate for 105 dies per year is $5.4 per die. Evaluation of the interaction of these materials in contact with molten silicon indicates that solid solutions based upon .beta.-Si3N4 are more stable than those based on Si2N2O. Sibeon is more resistant to molten silicon attack than Sialon, and both materials should preferably be used in an inert atmosphere rather than under vacuum conditions. This is because removal of oxygen from the silicon melt as SiO enhances the dissolution of aluminum and beryllium. The wetting angles of these materials are low enough (37° for x = 0.75 .beta.' Sialon and 49° for x = 0.35 Sibeon) for these materials to be considered as both die and container materials.

Download or read book Solar Energy Update written by and published by . This book was released on 1979 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study Program to Develop and Evaluate Die and Container Materials written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1980 with total page 1280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Evaluation of Die and Container Materials Second Quarterly Progress Report January 1 March 31 1978 For Molten Silicon written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Initial samples of four silicon aluminum oxynitride (Sialons) ceramics have been prepared from commercial Si3N4, Al2O3, AlN, and SiO2 powders by hot pressing at 1750 C. Si1.9Al0.1N1.9O1.1, Si1. Al0.2N1.8O1.2, and Si3.6Al2.4N5.6O2.4 Sialons were densified to greater than or equal to 90% theoretical density, but Si5.4Al0.6N--.4O0.6 Sialon could be pressed only to 72% theoretical density. None of these materials are single-phase materials; one group of samples contains an unidentified Sialon phase, while the other group contains significant amounts of free elemental silicon. Chlorine in the Si3N4 powder and free aluminum in the AlN powder are responsible for these effects. Initial evaluation of these materials in contact with molten silicon at 1450 C indicates that chemical reaction is occurring. Thin string-like precipitates found in the silicon after reaction with Si3.6Al2.4N5.6O2.4 Sialon are considered to be due to the presence of a second phase in the material. Electron probe analysis of silicon in contact with a Si1.8Al0.2N1.8O1.2 sample did not detect aluminum in the silicon, but two reaction zones were found at the interface. Solution thermodynamics studies show that beryllium oxide is much more resistant to attack than aluminum oxide. Fifteen weight percent aluminum dissolved in molten silicon compard with 5000 ppM beryllium. The Henry's Law Constants for oxygen, beryllium, and aluminum at concentrations less than or equal to 5000 ppM have been determined.

Download or read book Study Program to Develop and Evaluate Die and Container Materials for the Growth of Silicon Ribbons Quarterly Report written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Die and container material development efforts under the current program are shared among three organizations: Miami Research Laboratories (MRL) - ceramic process development and overall program management; University of missouri-Rolla (UMR) - silicon sessile drop studies with characterization of reaction products and emphasis on atmospheric effects; and Chemetal Corporation, Pacoima, California - special coatings to be applied to test coupons, die shapes, and containers provided by MRL and tested/characterized by UMR. The completion of a major hardware delivery milestone was accomplished with the delivery of three CNTD Si3N4 coated hot pressed Si3N4 crucibles to JPL. A limited characterization of the coating was performed at MRL prior to delivery. The coatings were fine grained .cap alpha. - Si3N4. It has been determined that a two piece die design will be required. At UMR the importance of the role of oxygen in influencing the attack of the CNTD materials by molten silicon has been demonstrated. The stability is greatly enhanced by maintaining the oxygen partial pressure near or below the Si + O2 = SiO2 equilibrium.

Download or read book Development and Evaluation of Die and Container Materials Third Quarterly Progress Report April 1 June 30 1978 For Molten Silicon written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods of producing low-cost silicon sheet for solar cells are under active development. In the crystal-growing processes a refractory crucible is required to hold the molten silicon, while in the ribbon processes an additional refractory shaping die is needed to enable silicon ribbon to be produced. In several ribbon processes the high-temperature materials are a limiting factor in the development of the technique. The objective of this study is to develop and evaluate refractory die and container materials. Mass spectrometric studies of molten silicon in contact with silicon nitride and silicon carbide show that the vapor pressure of silicon is lower over these materials than over the oxides (beryllium oxide, alumina, and silica) studied previously. Measured carbon and nitrogen contents are 6.4 x 1019 atoms/cm3 and 3.3 x 1018 atoms/cm3, respectively. The fabrication of O' and .beta.' Sialons was found to be strongly dependent upon the nature of the silicon nitride powder. A modified hot pressing procedure was adopted to allow volatilization of chlorine-containing species from the SN402 grade powder. .beta.' Sialon of composition X = 1 appears to offer some promise as a candidate die material, but materials containing a higher alumina composition (X = 2.4 Sialon) or the phase known as X phase with molten silicon. O' Sialons of compositions X = 0.1, X = 0.2, and X = 0.35 reacted with molten silicon, forming a complex interface zone. The concentration of thin precipitates in the silicon increased with the alumina content of the O' Sialon solid solution.

Download or read book Study program to develop and evaluate die and container materials written by Miami Research Laboratories and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study Program to Develop and Evaluate Die and Container Materials for the Growth of Silicon Ribbons written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Large Area Silicon Sheet Growth Task objective of lowering the cost of silicon photovoltaic material requires the development of materials which exhibit improved chemical and dimensional stability in contact with molten silicon. These materials may find application as containers and/or shaping dies in processes such as edge-defined film growth. The development and evaluation of proprietary coatings of pure silicon carbide, silicon nitride and aluminum nitride on less pure hot pressed substrates of the respective ceramic materials are described. Silicon sessile drop experiments were performed on coated test specimens under controlled oxygen partial pressures. X-ray diffraction and SEM Characterization was performed prior to testing. The reaction interfaces were characterized after testing with optical and scanning electron microscopy and Auger electron spectroscopy. Increasing the oxygen partial pressure was found to increase the molten silicon contact angle, apparently because adsorbed oxygen lowers the solid-vapor interfacial free energy. Adsorbed oxygen was also found to increase the degree of attack of molten silicon upon the chemical vapor deposited coatings. Prototypic containers and dies were delivered and cost projections show that reasonably priced, coated, molten silicon resistant refractory material shapes are obtainable.