REPLICATION TECHNIQUE FOR EXAMINING DEFECTS IN THE INTERFACE OF A METAL-TO-GLASS CERAMIC BOND

摘要

Epoxy replicas were made of the interface of a molybdenum and glass-ceramic assembly and examined by scanning electron micro¬scopy.nReplications of this interface were produced by first removing the molybdenum from four assemblies using a nitric acid-based etchant. The glass-ceramic insulators that remained were pres¬sure encapsulated in epoxy. After curing, the glass-ceramics were etched from the epoxy in an hydrogen fluoride-based acid etchant. The resulting replicas resembled the texture of the molybdenum surface with the interface defects shown in detail as projections. This process revealed some unusual interface problems which appeared to be associated with the evolution of gas from the molybdenum piece parts.