List three sources of variability in material properties If

List three sources of variability in material properties. If that variability can be reduced, describe how.

Solution

Homogeneous materials: A material of uniform composition throughout that cannot be mechanically separated into different materials. Examples of homogeneous materials are certain types of plastics, ceramics, glass, metals, alloys, paper, board and resins.

Isotropic materials: Isotropic material means a material having identical values of a property in all directions. Glass and metals are examples of isotropic materials.

Anisotropy materials: It is a term used in various scientific disciplines to indicate that certain properties of matter (such as a material or radiation) vary with the direction from which they are measured. For instance, if the refractive index or density of a material is different when measured along different axes, that property is said to be anisotropic.Anisotropy is the opposite of isotropic, a term used when properties are the same when measured from any direction.

Orthotropic materrials: In materials science and solid mechanics, orthotropicmaterials have material properties that differ along three mutually orthogonal twofold axes of rotational symmetry. They are a subset of anisotropic materials, because their properties change when measured from different directions.

A design is expected to have a good concept about mechanical properties of materials. Different manufacturing methods and heat treatment can change the materials properties.

Engineering materials are divided as follows:-

1. Metal and Metal Alloys; Example: Iron, Copper, Nickel etc.

2. Non- Metals; Example: Ceramics, rubber, glass etc.

Important Mechanical Properties of Materials are Described Below

a. Strength: This describes the ability to resist any external force. Without Yielding (Yield point is that point at which plastic deformation starts) breaks.

b. Stiffness: This is measured by modulus of elasticity. It is ability of the material to prevent deformation when stress is applied.

There are many mechanical properties are present .

The mechanical properties of a materialare those which effect the mechanical strength and ability of material to be molded in suitable shape. Some of the typical mechanical properties of a material are listed below-

Strength
Toughness
Hardness
Hardenability
Brittleness
Malleability
Ductility
Creep and Slip
Resilience
Fatigue