ABSTRACT
Selecting the appropriate material and manufacturing process is an important requisite for the development of a product that will perform successfully in service. It is estimated that there are more than 40,000 currently useful metallic alloys and probably close to that number of nonmetallic engineering materials such as plastics, ceramics and glasses, composite materials, and semiconductors. This large number of materials and the many manufacturing processes available to the engineer often make the selection process a difficult task. If the selection process is carried out haphazardly, there will be the risk of overlooking a possible attractive alternative solution. This risk can be reduced by adopting a systematic selection procedure. A rigorous and thorough approach to materials selection is, however, often not followed in industry, and much selection is based on past experience-“when in doubt make it stout out of the stuff you know about.” Although it is unwise to totally ignore past experience, since what worked before is obviously a solution, such solution may not be the optimum solution. The increasing pressure to produce more economic and competitive products, in addition to the frequent introduction of new materials and manufacturing processes, makes it necessary for the engineer to be always on the lookout for possible improvement.
