Callister - An introduction - 8th edition

WHY STUDY Economic, Environmental, and Societal Issues in Materials
Science and Engineering?
It is essential for the engineer to know about and
understand economic issues simply because the company/
institution for which he or she works must realize a
profit from the products it manufactures. Materials
engineering decisions have economic consequences
with regard to both material and production costs.
An awareness of environmental and societal issues
is important for the engineer because, over time,
greater demands are being made on the world’s natural
resources. Furthermore, levels of pollution are ever
increasing. Materials engineering decisions have impacts
on the consumption of raw materials and energy, on
the contamination of our water and atmosphere, on
human health, on global climate change, and on the
ability of the consumer to recycle or dispose of spent
products. The quality of life for this and future generations
will depend, to some degree, on how these issues
are addressed by the global engineering community.
Learning Objectives
After studying this chapter you should be able to do the following:
1. List and briefly discuss three factors over which
an engineer has control that affect the cost of
a product.
2. Diagram the total materials cycle, and briefly
discuss relevant issues that pertain to each
stage of this cycle.
3. List the two inputs and five outputs for the life
cycle analysis/assessment scheme.
4. Cite issues that are relevant to the “green
design” philosophy of product design.
5. Discuss recyclability/disposability issues relative
to (a) metals, (b) glass, (c) plastics and rubber,
and (d) composite materials.
22.1 INTRODUCTION
In previous chapters, we dealt with a variety of materials science and materials engineering
issues to include criteria that may be employed in the materials selection
process. Many of these selection criteria relate to material properties or property
combinations—mechanical, electrical, thermal, corrosion, and so on; the performance
of some component will depend on the properties of the material from which
it is made. Processability or ease of fabrication of the component may also play a
role in the selection process. Virtually all of this book, in one way or another, has
addressed these property and fabrication issues.
In engineering practice, other important criteria must be considered in the development
of a marketable product. Some of these are economic in nature, which,
to some degree, are unrelated to scientific principles and engineering practice, and
yet are significant if a product is to be competitive in the commercial marketplace.
Other criteria that should be addressed involve environmental and societal issues
such as pollution, disposal, recycling, toxicity, and energy. This final chapter offers
relatively brief overviews of economic, environmental, and societal considerations
that are important in engineering practice.
Economic Considerations
Engineering practice involves using scientific principles to design components and
systems that perform reliably and satisfactorily. Another critical driving force in engineering
practice is that of economics; simply stated, the company or institution
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