Overview

Machining often produces subsurface defects that while not seen do affect product performance. Traditionally the study of this aspect of machining is defined as surface integrity. That is not a common term when ceramics or composite materials are discussed. There are at least three different systems used to define the surface and subsurface condition. Table 8-1 presents the major aspects of these three systems. Burrs and external distortion are also common to both metals and composites. They are unwanted side effects, but are not subsurface issues. Burrs can produce integrity issues such as reduction in part life or load-carrying ability. Some ceramics are fiber-reinforced and are therefore composite materials also, but for this chapter "composites" will refer to plastic and metal combinations. Glass and ceramics do not have the same underlying structures and including them together in the table hides this fact, but this is not significant for the purpose of this chapter.