Chapter 4 & 5 Materials Flashcards
Brittle
A material that does not plastic ally deform before breaking Breaks suddenly as cracks travel through it
Strong
A material that can withstand large amounts of stress before breaking
Tough
A material that undergoes considerably plastic deformation before breaking. In this process it will also absorb a lot of energy before breaking
Stiff
Small strains for large stresses Large Young modulus Not stretchy or bendy
Elastic
Returns to unstretched form when stresses are removed
Plastic
Undergoes permanent deformation under large stresses rather than cracking
Hard
Resists indentation on impact
Limit of proportionality
Point beyond which stress and strain are no longer proportional Hooke’s law does not apply
Yield point
Point at which strain increases rapidly
Ultimate Tensile Strength UTS
Stress at which a material breaks
Ductile
Can be drawn out into wires Undergoes considerable plastic deformation before breaking
Hysteresis loop
Loading and unloading cycle for rubber Area of the loop equals the energy per unit volume transferred to heat inside the rubber
What structure does this material have
Amorphous
What structure does this material have?
Crystalline
What structure does this material have
Polycrystalline