Examination of Selected NDE Techniques for Ceramic Composite Components

Abstract

Nondestructive techniques are needed to detect defects, monitor the various states of material, and characterize damage development in ceramic matrix composite (CMC) specimens and components. Although some nondestructive examination (NDE) methods yield more information than others, generally no one method will provide all the required information. Therefore, a combination of NDE methods is necessary to fully investigate specimens and components before, during, and after testing. This paper examines a variety of NDE methods to meet these needs. The investigation covers a wide variety of methods from typical optical microscopy to highly developmental techniques such as acoustoultrasonics and scanning acoustic microscopy. The paper provides an information base on the application of NDE techniques to ceramic composites to assist researchers in planning and selecting NDE methods for CMCs. The paper is divided into three main sections. The first section briefly describes the fabrication of the specimen and the mechanical test series. The second section contains a discussion of the application of selected NDE methods and a short synopsis of each of the methods examined. The third section summarizes the NDE results in conjunction with the mechanical test results. In this section, a correlation of the initial defects, observed damage development, and failure surface analysis is provided to identify the critical performance limiting defects in chopped fiber-reinforced borosilicate glass tubes.