9 - Corrosion of ceramic materials

Abstract

The term ceramic inclined us to think of tiles, pots, and has been accompanied with human race from ancient days. The last century has seen an exponential explosion in engineering developments that would not have been possible without ceramics. Today the ceramic materials are considered as a special category due to excellent properties such as high melting points, low electrical and thermal conductivity values, and high compressive strengths and these ceramic materials have extended their hands in various fields including electronic devices, computer, dentistry, biomedical, and aerospace engineering. This vast role of ceramic material in day-to-day life makes us to identify the problem of corrosion that occurs in ceramic. Even though the term corrosion was generally associated with metals, ceramic materials also undergo unintentional degradation in contact with environment. Generally corrosion is a system property rather than a simple material property, and today the impact of corrosion on society and the related deterioration of materials lead to the increased complexity and diversity of material system including ceramics, which are not susceptible to electrochemical degradation due to its poor conductor property but due to the simple dissolution of the material. In recent years, there was significant advancement in the study on the interaction between corrosion and erosion in ceramics. In general, the corrosion in ceramics material is not instantaneous and this chapter sheds over some light on better understanding of the mechanism involved in corrosion-erosion of ceramic materials. This chapter glances over the direct relationship of corrosion to the property degradation and also explains in detail the various testing procedures adopted for the evaluation of material stability. One of the most important properties affected by corrosion was its mechanical strength. The advancement of ceramic material in dentistry was inevitable due to its different microstructures, chemical composition, properties, and these ceramics materials were generally corroded in acidic medium. Hence, in this chapter, we elaborate the effects of erosion on ceramic on the surface roughness, flexural strength, and exposure to various environments including acidic medium. We also discussed the methods adopted to minimize the ceramic corrosion.