Materials Science/Materials

Materials

Materials are physical substances used as inputs to production or manufacturing. Raw materials are first extracted or harvested from the earth and divided into a form that can be easily transported and stored, then processed to produce "semi-finished materials". These can be input into a new cycle of production and "finishing processes to create "finished materials", ready for distribution and consumption.

An example of a raw material is cotton, which can be processed into thread, and then processed into cloth, a semi-finished material. Sewing and cutting the fabric turns it into a garment, which is a finished material. Steelmaking is another example—raw materials are extracted, refined and processed into steel, a semi-finished material. Steel is then used as an input in many other industries to make finished products.

Partial Comparison of Materials

Type	Bonding	Properties	Thermal/electrical conductivity	optical
Metals	Metallic		high	opaque, reflective
Polymers	Secondary	soft, ductile, low strength	insulators	translucent/ transparent
Ceramics	Mostly Ionic	brittle, glassy, elastic	Insulators
Semiconductors	covalent	??	Between conductors and insulators