These volumes constitute the Proceedings of a Symposium on the Fracture Mechanics of Ceramics, held at the Pennsylvania State University, University Park, Pennsylvania, July 11, 12, and 13, 1973. The theme of the symposium focussed on the mechanical behavior of brittle ceramics in terms of the characteristics of cracks. The 52 contributed papers by 87 authors, present an overview of the cur­ rent understanding of the theory and application of fracture mechan­ ics to brittle ceramics. The program chairmen gratefully acknowledge the financial assistance for the Symposium provided by the Office of Naval Re­ search, the College of Earth and Mineral Sciences of the Pennsyl­ vania State University, the Materials Research Center of Lehigh University, Bethlehem, Pennsylvana and Westinghouse Research Laboratories, Pittsburgh, Pennsylvania. Special appreciation is extended to the expert organization provided by the J. Orvis Keller Conference Center of the Pennsyl­ vania State Conference Center of the Pennsylvania State University. In particular, Mrs. Patricia Ewing should be acknowledged for the excellent program organization and planning. Dean Harold J. O'Brien, who was featured as the after-dinner speaker and who presented a most stimulating talk on the communication between people, also contrib­ uted to the success of the meeting. Finally, we also wish to thank our joint secretaries for the patience and help in bringing these Proceedings to press. University Park R. C. Bradt Bethlehem D. P. H. Hasselman Pittsburgh, Pennsylvania F. F. Lange July, 1973 v CONTENTS OF VOLUME 1 Contents of Volume 2 . . . . . . . . . . . . . . . . . . .

Inhalt

OF Volume 1.- I. Fracture Mechanics Applied to Ceramics.- Origin and Use of Fracture Mechanics.- Fracture Mechanics Determinations.- Determination of Elastic Constants Required for Application of Fracture Mechanics to Ceramics.- Conventional Strength Testing of Ceramics.- Statistics of Brittle Fracture.- II. Flaw Detection and Theoretical Aspects of Fracture Mechanics.- Overview of Nondestructive Inspection Techniques.- Origin and Detection of Microflaws in Glass.- Microstructural Aspects of Acoustic Emission Generation in Ceramics.- Surface Evaluation Using Acoustic Emission.- Observation of Crack Propagation in Polycrystalline Ceramics and Its Relationship to Acoustic Emissions.- The Initiation and Propagation of Hertzian Ring Cracks.- The Interaction between Inclusions and Cracks.- Analysis of Cracks in Heterogeneous Solids.- Crack Morphology in Relatively Brittle Crystals.- Theory of Dynamic Strength.- III. Fractography.- Fracture Mirrors in Polycrystalline Ceramics and Glass.- Fractographic Identification of Strength-Controlling Flaws and Micro structure.- Fracture Mechanics, Statistical Analysis and Fractography of Carbides and Metal Carbides Composites.- Inclusion Effects on the Strength of Hot Pressed Si3N4.- Auger Spectroscopy of Fracture Surfaces of Ceramics.- Scanning Electron Fractographic Study of Aluminum Oxide Function of Testing Temperature and Grain Size.- Quantitative SEM and Raster Profilometer Analysis of Fracture.- Tensile Fragmentation of Virgin Glass Fibers.- Contributor.