Mechanical Properties of Materials

Vocabulary flashcards covering the mechanical properties of metals, design/safety factors, advanced materials, and shape memory alloys.

Yield Strength

The stress at which plastic deformation begins in a metal.

Tensile Strength

The maximum tensile stress that can be sustained by a specimen.

Ductility

A measure of the degree of plastic deformation under tensile stress by the time fracture occurs.

%EL (Percent Elongation)

A measure of ductility, calculated as ((final length - initial length) / initial length) * 100.

Ductile Materials

Materials with a large %EL; examples include mild steel, aluminum, brass, molybdenum, and zinc.

Brittle Materials

Materials with a small %EL (below 5%); an example is gray cast iron.

Malleability

The property of a metal to deform plastically under compressive stress and take on a new shape; ability to be hammered, pressed, or rolled into thin sheets without breaking.

Fracture Toughness

A property that shows material’s resistance to fracture when a crack is present.

Hardness

A measure of a material’s resistance to localized plastic deformation.

Safe Stress (Working Stress)

Based on the yield strength of the material and is defined as the yield strength divided by a factor of safety, N. σw = σy / N

Advanced Materials

Materials utilized in high-technology applications that operate using relatively sophisticated principles. Examples include smart materials, semiconductors, biocompatible materials, nanomaterials and meta-materials.

Shape Memory Alloys (SMA)

Materials that, after being deformed, have the ability to return to their pre-deformed size and shape upon being subjected to an appropriate heat.

Transformation Temperature

The temperature at which the deformation of a shape memory alloy starts to recover.

Martensitic Phase

A phase transformation of Shape Memory Alloys (SMA) by cooling.

Austenite

A phase transformation of Shape Memory Alloys (SMA) by heating.