Introduction

	University of Nevada Las Vegas		MEG301 Structures and Properties of Solids
	Department of Mechanical Engineering		Fall Semester 2000

Introduction

Materials are substances of which something is composed or made.

Materials Science is primarily concerned with the search for basic knowledge about the internal structure, properties, and processing of materials.

Materials Engineering is mainly concerned with the use of fundamental and applied knowledge of materials so that the materials can be converted into products necessary or desired by society.

Type of Materials

Metallic

Polymeric

(Plastic)

Ceramic

Composite

Electronic

Metallic Materials: are inorganic substances with one or more metallic elements such as iron, copper, aluminum, nickel, and titanium, and may also contain some nonmetallic elements, such as carbon, nitrogen, and oxygen.

Structure:

Metals have a crystalline structure.

Property (in general):

Good thermal and electrical conductors; good strength; ductile.

Classes:

Ferrous metals and alloy: contains a large percentage of iron such as the steels and cast irons.

Nonferrous metals and alloys do not contain iron or only a relatively small amount of iron, such as aluminum, copper, zinc, titanium, and nickel.

Polymeric Materials: are organic (carbon-containing) long molecular chains or networks.

Structure:

Mostly are noncrystalline but some consist of mixtures of crystalline and noncrystalline regions.

Property (in general):

Strength and ductility varies greatly; poor thermal and electrical conductors; low densities, and low softening or decomposition temperatures.

Ceramic Materials: are inorganic materials that consist of metallic and nonmetallic elements chemically bonded together.

Structure:

Can be crystalline, noncrystalline, or mixtures of both.

Property (in general):

High hardness, high-temperature strength, good heat and wear resistance, brittle.

Composite Materials: are mixtures of two or more materials, consists a selected filler or reinforcing material and a compatible resin binder to obtain the specific characteristics and properties desired.

Structure:

The filler components do not dissolve in matrix and can be physically identified by an interface between the components.

Classes:

Fibrous composites are composed of fibers in a matrix.

Examples: fiberglass-reinforcing material in a polyester or epoxy matrix, carbon fibers in an epoxy matrix.

Particulate composites are composed of particles in a matrix.

Electronic Materials: is pure silicon, which is modified in various ways to change its electrical characteristics.

Created by Dr. Wang