ISO INTERNATIONAL STANDARD 18550 First edition 2016-03-01 Fine ceramics (advanced ceramics, advanced technical ceramics) - Testing method for macro- heterogeneity in microstructure Céramiques techniques-Méthode d'essai relative aux macro- héterogénéités dans la microstructure Reference number ISO 18550:2016(E) ISO International Organization for Standardization ZHEJIANG INSTOFSTANDARDIZATION C15956617 @IS02016 vided by IHS under ted without license from IHS IS0 18550:2016(E) COPYRIGHTPROTECTEDDOCUMENT IS0 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. IsOcopyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org ensee-ZHEJIANG INST.OF STANDARDIzARoISQ16- All rights reserved Iby IHS unde etworking permitted without license from IHS IS0 18550:2016(E) Contents Page Foreword ..iv 1 Scope 2 Normative references .1 3 Terms and definitions ..1 4 Principle 5 Apparatus. .1 6 Test specimen .2 7 Procedure. .2 7.1 Measurement of specimen thickness .2 7.2 Observation .2 7.3 Magnification .2 8 Measurement of macro-heterogeneities .3 8.1 Determination of specimen volume under examination 3 8.2 Measurement of the size of macro-heterogeneities 3 9 Analysis .3 9.1 Maximum and minimum size .3 9.2 Size interval .3 9.3 Size and population of defect. .3 9.4 Graph 4 10 Test report ..4 Annex A (informative) Refractive indices of solid and liquids .5 Annex B (informative) Examples of macro-heterogeneities observed in transmission mode .6 Bibliography 9 iii thout license from IHS