Manufacturing Materials



In Manufacturing Four types of materials are used. Their chemistries are different, their mechanical and physical properties are dissimilar, and these differences affect the manufacturing processes that can be used to produce products from them

1. Metals
2. Ceramics
3. Polymers
4. Composites


Metals

In manufacturing metals are used usually in the form of  alloys, which are composed of two or more elements, at least one of which is metal

Metals used in manufacturing are classified into Two basic groups:

1. Ferrous metals - based on iron, comprise 75% of metal tonnage in the world:
  •  Steel = iron-carbon alloy with 0.02 to 2.11% C
  •  Cast iron = alloy with 2% to 4% C
2. Non ferrous metals - all other metallic elements and their alloys: aluminium, copper, gold, magnesium, nickel, silver, tin, titanium, etc.


Ceramics

A compound containing metallic (or semi-metallic) and non metallic elements. Typical nonmetallic elements are oxygen, nitrogen, and carbon

For manufacturing processing purposes, ceramics divide into:

1. Crystalline ceramics –includes:
  • Traditional ceramics, such as clay (hydrous aluminium silicates)
  • Modern ceramics, such as alumina (Al2O3)
2. Glasses –mostly based on silica (SiO2)


Polymers

A compound formed of repeating structural units called mers, whose atoms share electrons to form very large molecules

For manufacturing processes polymers are classified in Three categories:

1. Thermoplastic polymers - can be subjected to multiple heating and cooling cycles without altering their molecular structure

2. Thermosetting polymers - molecules chemically transform (cure) into a rigid structure upon cooling from a heated plastic condition


3  Elastomers - exhibit significant elastic behavior


Composites 

A material consisting of two or more phases that are processed separately and then bonded together to achieve properties superior to its constituents
  • A phase = a homogeneous mass of material, such as grains of identical unit cell structure in a solid metal
  • Usual structure consists of particles or fibers of one phase mixed in a second phase
  • Properties depend on components, physical shapes of components, and the way they are combined to form the final material