Replicas as a Technique for Examining Fracture Surfaces of Ceramics

This paper discusses reasons for using replicas of fracture surfaces of ceramics, describes several replicating methods and materials, and presents examples that compare replicas with actual fracture surfaces. Advantages of using replicas include being able (1) to examine large pieces without having to cut them down to size, (2) to provide convenient archiving of fracture surfaces, and (3) to eliminate sub-surface scattering of light. Many times, replicas provide clearer views of untreated (uncoated) fracture surfaces than can be obtained by direct observation. Replication using cellulose acetate tape and two types of silicone rubber (filled and unfilled) are described. Both methods are fast, relatively inexpensive, and non-destructive. Images of replicas of fracture surfaces of a glass and several ceramic materials (including electrical porcelain and several polycrystalline ceramics) are compared with images of actual fracture surfaces.