Prof. Satish V. Kailas
Dept. of Mechanical Engineering,
Indian Institute of Science,
Bangalore – 560012
Chapter 9. Applications and Processing of Metals and Alloys
In the materials world we are living in, when making a new device/component, most
often we come across a very familiar problem. This is nothing but select the right
material. As learnt in earlier chapter, selection of material can play very important role
preventing failures. Selection of material for a specific purpose depends on many factors.
Some of the important ones are: strength, ease of forming, resistance to environmental
degradation, etc. Another dimension an engineer should be aware of it is how to tailor the
required properties of materials.
As introduced in one of the earlier chapters, materials can be are broadly classified as
metals, ceramics and plastics. This chapter introduces different classes of metallic
materials, common fabrication methods, and means to alter their properties on purpose.
Following chapters deal with ceramic materials and plastic materials.
9.1 Types of metals and alloys
Metallic materials are broadly of two kinds – ferrous and non-ferrous materials. This
classification is primarily based on tonnage of materials used all around the world.
Ferrous materials are those in which iron (Fe) is the principle constituent. All other
materials are categorized as non-ferrous materials. Another classification is made based
on their formability. If materials are hard to form, components with these materials are
fabricated by casting, thus they are called cast alloys. If material can be deformed, they
are known as wrought alloys. Materials are usually strengthened by two methods – cold
work and heat treatment. Strengthening by heat treatment involves either precipitation
hardening or martensitic transformation, both of which constitute specific heat treating
procedure. When a material can not be strengthened by heat treatment, it is referred as