6 Flashcards
What is density?
Mass per unit volume
What is density measured in?
Kg/m3
What is fatigue?
When something is subjected to cyclic loading
Where does fatigue start?
A stress concentrator (scratch or indent)
How is stress defined?
Force per unit area
What is stress measured in?
N/m2 or pascals
What is tensile stress?
When an object is under tension
What is compressive stress?
When an object is under compression
What is shearing stress?
When an object is under shear
What is combined stress?
When an object has a combination of tensile or compressive stress and shearing stress
What is simple stress?
When there is only one type of stress acting on an object
What is unit strain?
The amount of deformation divided by original shape
What is poissons ratio?
When an object is pulled apart it will get thinner and visa verca
What is the definition of hardness?
The ability to resist penetration, wear or cutting
What is the definition of strength?
The ability to withstand forces which tend to deform the metal
What is the definition of elasticity?
The ability to return to its original shape after deformation
What is the definition of plasticity?
The property of a metal which allows it to be reshaped
What is the definition of ductility?
The ability for metal to be drawn into thinner sections
What is the definition of malleability?
The ability to being beaten or rolled without breaking
What is the definition of toughness?
The ability to be deformed without breaking
What is the definition of brittleness?
The property of an object to break when deformed
What is the definition of conductivity?
The ability to transmit heat or electricity
What is the definition of durability?
The ability to withstand forces over a period of time
What is a metallic material?
Having the nature of metal or containing metal
What is a non-metallic material?
Contains no metal
What is a ferrous material?
Any metal that contains iron
What is a non-ferrous metal?
A metal that contains little or no iron
What is the elastic limit of an object?
The maximum stress to a material and still return to original shape
What is yield strength of an object?
The maximum stress that can be applied without permanent deformation
What is the tensile strength of an object?
The maximum value of tensile stress that a material can withstand without breaking
How is tensile strength calculated?
Maximum tensile force divided by original cross-sectional area
How many atoms does a body centred cubic unit cell have?
9 atoms
How many atoms does a face cantered cubic unit cell have?
14 atoms
How many atoms does a hexagonal close packed unit cell have?
17 atoms
A change in material in existing programmes will result in?
A new airworthiness certification
