Thermal properties

Question 1

What is the coefficient of thermal expansion?

Answer 1

The amount by which a solid material expands per degree K temperature rise

Question 2

What can be the result in a difference in CTE between adjoining materials?

Answer 2

Stresses due to different amounts of expansion

Question 3

Describe 2 processes in which a material thermally conducts?

Answer 3

Lattice vibrations - Excited atoms in one area share energy with their neighbours
Free electrons - Electrons are excited in the high temperature areas and travel to the low temperature areas where they give up their excess kinetic energy to other electrons and atoms

Question 4

Describe how thermal shock occurs

Answer 4

When an object is heated or cooled its exterior will usually have a different temperature to its interior. If say rapidly cooled the outer will cool faster than the inner and contract faster than the interior leading to tensile stresses in the outer areas and compressive in the inner.