Flashcards in Chapter 4 Deck (19):
Weight per unit Volume
Define: Specific Gravity
Density of a material relative to the density of water and is therefore a ratio with no units
Define: Thermal Expansion
Measures the change in length per degree of temperature. Length ratio.
Define: Melting Point
Temperature at which the material transforms from a solid to liquid state
Define: Freezing Point
Temperature at which the material transforms from a liquid to solid state
Define: Heat of Fusion
Amount of heat energy need to accomplish phase changes from solid to liquid and vice versa.
Define: Supercooled Liquid
When an element remains a liquid even at temperatures below its freezing point; due to nucleation of crystals not initiating immediately
In metal alloys, melting begins at a certain temperature (solidus), which continues to rise as full transition from solid to liquid occurs
In metal alloys, when all material is in the liquid state, the temperature is referred to as (liquidus)
Define: Specific Heat
Quantity of heat energy required to increase the temperature of a unit mass of the material by one degree. (C: J/kg-K)
Define: Thermal Conductivity
"k": J/s-mm-K ; the capacity of a substance to transfer heat through itself by physicial mechanism
Basic electrical property that defines a material's capability to resist current flow; "r".
Basic electrical property that defines a material's capability to conduct current flow; "c".
c = 1/r
Metals with low resistivity.
Materials with high resistivities
Term given to insulators to mean a "nonconductor of direct current". However, if the voltage is high enough, current will form an arc and pass.
Exhibits zero resistivity and observed in certain materials at low temperatures approaching absolute "0".
Material whose resistivity lies between insulators and conductors; commonly used element: silicon. Useful in fabricating integrated circuits.