• PDF / 5,422,536 Bytes
• 260 Pages / 439.37 x 666.14 pts Page_size
• 71 Downloads / 384 Views

DOWNLOAD

REPORT

---

Emad El-Meliegy



Richard van Noort

Glasses and Glass Ceramics for Medical Applications

Emad El-Meliegy Department of Biomaterials National Research centre Dokki Cairo, Egypt [email protected]

Richard van Noort Department of Adult Dental Care School of Clinical Dentistry Sheffield University Claremont Crescent Sheffield, UK [email protected]

ISBN 978-1-4614-1227-4 e-ISBN 978-1-4614-1228-1 DOI 10.1007/978-1-4614-1228-1 Springer New York Dordrecht Heidelberg London Library of Congress Control Number: 2011939570 © Springer Science+Business Media, LLC 2012 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)

Preface

Glass-ceramics are a special group of materials whereby a base glass can crystallize under carefully controlled conditions. Glass-ceramics consist of at least one crystalline phase dispersed in at least one glassy phase created through the controlled crystallization of a base glass. Examples of glass-ceramics include the machinable glass-ceramics resulting from mica crystallization, the low thermal expansion glass-ceramics resulting from β-eucryptite and β-spodumene crystallization, high toughness glass-ceramics resulting from enstatite crystallization, high mechanical strength resulting from canasite crystallization or the high chemical resistance glass-ceramic resulting from mullite crystallization. These materials can provide a wide range of surprising combinations of physical and mechanical properties as they are able to embrace a combination of the unique properties of sintered ceramics and the distinctive characteristics of glasses. The properties of glass-ceramics principally depend on the characteristics of the finely dispersed crystalline phases and the residual glassy phases, which can be controlled by the composition of the base glass, the content and type of mineralizers and heat treatment schedules. By precipitating crystal phases within the base glasses, exceptional novel characteristics can be achieved and/or other properties can be improved. In this way, a limitless variety of glass-ceramics can be prepared with various combinations of different crystalline and residual glassy phases. With the appropriate knowledge on the right way to modify the chemical compositions and the heat treatment schedules, one ca