UConn MSE-2101 Exam 2

Deformation

Process of coordinated atomic movement using dislocations.

ways materials can be deformed

Tension

Compression

Shear

Torsion

Stress States

simple tension

simple compression

Elastic Modulus

Initial linear slope of stress strain plot

Necking

starts after UTS is reached

Ultimate Tensile Strength

Maximum strength in the engineering stress strain curve

Young's modulus/elastic modulus

linear slope of stress strain plot

yield strength

Stress at which material begins to "yield". stress-strain curve ceases to be linear.

Ductility: %EL and %AR

Max amount of plastic deformation. measured by tensile strain after failure

Toughness [J/m^3 ]

Measure of the ability to absorb energy up to fracture. Approximates to the area under the stress-strain curve.

Resilience, Ur

Ability of a material to store mechanical energy

1/2stressstrain under linear portion

Hardness

Resistance to permanently indenting the surface

Plastic deformation

Material is deformed such that it cannot return to its original dimension

Slip system

The combination of a slip plane and slip direction.

Dislocation Density

The total dislocation length per unit volume. The number of dislocations that intersect a unit area.

Schmid's Law

The relationship between uniaxial stress action on a cylinder of pure metal single crystal and resulting resolved shear stress produced on a slip system.

Critical resolve shear stress

The stress required to cause slip in a pure metal single crystal.