TABLE OF CONTENTS The main goal in defining process attributes is to identify the characteristics that discriminate between processes, to enable their selection by screening. Each of the three process families shaping, joining and surface treatment has it own set of characterizing attributes, described here and in the next three sections. It is also of interest to explore the physical limits to these for a given process, and to examine how the properties of the material being processed limit the rate of the process itself.
One process attribute applies to all three families compatibility with material so we examine this first.
Figure 18.2 shows a material-process compatibility matrix. Shaping processes are at the top, with compatible combinations marked by dots the color of which identifies the material family. Its use for screening is straightforward specify the material and some processes are immediately eliminated (or the reverse, as a screening step in material selection). The diagonal spread of the dots in the matrix reveals that each material class metals, polymers, etc. has its own set of process routes. This largely reflects the underlying process physics. Shaping is usually eased by melting or softening the material, and the melting temperatures of the material classes are quite distinct (Figure 13.6). There are some overlaps powder methods are compatible with both metals and ceramics, molding with both polymers and glasses. Machining (when used for shaping) is compatible with almost all families. Joining processes using adhesives and fasteners are very versatile and can be used with most materials,...
