General Properties Flashcards
What is the thermal expansion relationship?
deltaL = alpha * L * deltaT
Define the heat of fusion.
The heat energy required at the melting temperature to transform a material from solid to liquid
What is the glass transition?
The softening the happens to amorphous materials between the solid and liquid states.
Define specific heat.
The quantity of heat energy required to increase temperature of a unit mass by one degree.
H = C W deltaT
H is heat, C is specific heat, W is weight
What is thermal conductivity?
A material’s ability to transfer heat through itself. (no mass transfer, simply energy transfer).
Metals do this better than ceramics and plastics.
How is mass diffusion used in industry?
Diffusion welding, where the mass transfer creates a permanent bond.
What bonds conduct electricity well? Which do not?
Metallic bonds are good conductors, ionic/covalent are not.
What is the most common semiconductor? Why are semiconductors important?
Silicon
They can alter their conductivity and be direction dependent.
How does an electrochemical cell work?
Ions dissolve in solution and separate to positive and negative poles, sending current through a connector.
What is the difference between toughness and resilience?
Toughness - whole curve
Resilience - elastic region only
What effect does temperature have on tensile strength?
What effect does strain rate have on tensile strength?
Higher temp = lower strength
Higher strain rate = higher strength
