This completely revised edition features new sections on glass-ceramic applications and their performance, CDC-grinding, and laser gyroscopes containing Zerodur®., providing an overview of Schott's activities for scientists, engineers, and managers.

This book, entitled Low Thermal Expansion Glass Ceramies, is one of aseries reporting on research and development acitivites on products and processes conducted by the Schott Group. The scientifically founded development of new products and technical pro cesses has traditionally been of vital importance at Schott and has always been performed on a sc ale determined by the prospects for application of our special glasses. The scale has increased enormously since the reconstruction of the Schott Glaswerke in Mainz. The range of expert knowledge required for that could never have been supplied by Schott alone. It is also a tradition in our company to cultivate collaboration with customers, universities, and research institutes. Publications in numerous technical journals, which since 1969 we have edited to a regular timeplan as Forschungsberichte - 'research reports' - formed the basis of this cooperation. They contain up-to-date infor mation on various topics for the expert but are not suited as survey material for those whose standpoint is more remote. This is the point where we would like to place our series, to stimulate the exchange of thoughts, so that we can consider from different points of view the possibilities offered by those incredibly versatile materials, glass and glass ceramics. We would like to show scientists and engineers, interested customers, and friends and employees of our firm the knowledge that has been won through our research and development at Schott in cooperation with the users of our materials.

This book is one of a series reporting on international research and development activities conducted by the Schott group of companies. With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest. Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated. This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics. The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions. Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization. Thus glass ceramics with thermal coefficients of expansion of less than 0.3 x 10( -6)K( -1) can be obtained. Even for the mass production of high-quality cooktop panels (Ceran (R)), oven windows, and other household appliances a high reproducibility of the properties is achieved. Special glass ceramics (Zerodur (R)) for technological and scientific applications such as high-precision optics or large astronomical mirrors are equally discussed.

This book examines exciting advancements in the field of ceramics, including nanotechnology, clean energy, and tribology as well as fundamental concepts like defects and structure. It is a comprehensive discussion on how today’s ceramics are processed and used in many of today’s critical technologies. It discusses current techniques for synthesizing durable and cost-effective ceramic components with biocompatibility, complexity, and high precision. This book is a comprehensive reference for researchers, engineers, dental clinicians, biologists, academics, and students interested in ceramics.

Glass ceramics were studied, formulated in the Na2O CaO. P2O5, Na2O. BaOP2O5, Na2O. Al2O3.P2O5, and Li2O. BaO. P2O5 systems to establish their suitability for sealing to high thermal expansion metals, e.g. aluminum, copper, and 300 series stainless steels. Glass ceramics in Na2O. CaO. P2O5 and Na2O. BaO. P2O5 systems have coefficients of thermal expansion in the range 140 x 10−1 per °C less than or equal to .cap alpha. less than or equal to 225 x 10−7 per °C and fracture toughness values generally greater than those of phosphate glasses; they are suitable for fabricating seals to high thermal expansion metals. Crystal phases include NaPo3, (NaPO3)3, NaBa(PO3)3, and NaCa(PO3)3. Glass ceramics formed in the Na2O. Al2O3.P2O5 systems have coefficients of thermal expansion greater than 240 x 10−7 per °C, but they have extensive microcracking. Due to their low thermal expansion values (.cap alpha. less than or equal to 120 x 10−7 per °C), glass ceramics in the Li2O. BaO. P2O5 system are unsuitable for sealing to high thermal expansion metals.