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There are many outstanding materials with highly desirable mechanical properties and corrosion resistance that are seldom used because they cannot be fabricated. There are some materials which have excellent properties that can be fabricated as produced but, because of aging, cannot be modified or repaired after exposure to operating conditions. Materials should therefore be selected on the basis of their maintainability as well as their original fabricability. A modern and comprehensive document on the subject is the second edition of the classic CORROSION BASICS textbook.
In general, the wrought heat resistant alloys have greater fabricability than the cast materials. Cast alloy steels, for example, can typically tolerate significantly higher concentrations of carbon, silicon, tungsten, molybdenum, etc., which are added to enhance mechanical properties, corrosion resistance, or both. But, these elements also can adversely affect the original, as-produced fabricability and make maintainability, particularly weldability, difficult, if not impossible.
In materials processing, parts are manufactured from a variety of materials to meet defined product specifications. The ever increasing concerns with performance and cost faced by companies competing in the global marketplace require that a spectrum of issues in the science of manufacturing be addressed. Innovations and improvements in the processing of materials result from advances in the fundamental understanding of the relationships between the process, the material, and the resulting product. Novel processing methodologies or the processing of new materials can open up opportunities for new product development, for research leading to next-generation machines and/ or improvements in product performance and cost. The advances being made in rapid prototyping, thin film and nanotechnologies, and net shape manufacturing are illustrations of the application of fundamental research to materials processing issues.
