Materials Engineering, Science, Processing and Design

Science-led or Design-led? Two approaches to materials teaching

Most things can be approached in more than one way. In teaching this is especially true. The way to teach a foreign language, for example, depends on the way the student wishes to use it—to read the literature, say, or to find accommodation, order meals and buy beer. So it is with the teaching of this subject.

The traditional approach to it starts with fundamentals: the electron, the atom, atomic bonding, and packing, crystallography and crystal defects. Onto this is built alloy theory, the kinetics of phase transformation and the development of microstructure on scales made visible by electron and optical microscopes. This sets the stage for the understanding and control of properties at the millimeter or centimeter scale at which they are usually measured. The approach gives little emphasis to the behavior of structures, methods for material selection, and design.

The other approach is design-led. The starting point is the need: the requirements that materials must meet if they are to perform properly in a given design. To match materials to designs requires a perspective of the range of properties they offer and the other information that will be needed about them to enable successful selection. Once the importance of a property is established there is good reason to ‘drill down’, so to speak, to examine the science that lies behind it—valuable because an understanding of the fundamentals itself informs material choice and usage.

There is sense in both approaches. It depends on the way the student wishes to use the information. If the intent is scientific research, the first is the logical way to go. If it is engineering design, the second makes better sense. This book follows the second.

What is different about this book?

There are many books about the science of engineering materials and many more about design.

What is different about this one?

First, a design-led approach specifically developed to guide material selection and manipulation.

The approach is systematic, leading from design requirements to a prescription for optimized material choice. The approach is illustrated by numerous case studies. Practice in using it is provided by Exercises.

Second, an emphasis on visual communication and a unique graphical presentation of material properties as material property charts. These are a central feature of the approach, helpful both in understanding the origins of properties, their manipulation and their fundamental limits, as well as providing a tool for selection and for understanding the ways in which materials are used.

Third, its breadth. We aim here to present the properties of materials, their origins and the way they enter engineering design. A glance at the Contents pages will show sections dealing with:

• Physical properties

• Mechanical characteristics

• Thermal behavior

• Electrical, magnetic and optical response

• Durability

• Processing and the way it influences properties

• Environmental issues