Material selection, Light Alloys and Titanium Flashcards
Material selection factors
mechanical properties mass temperature range corrosion susceptibility wear resistance formability special properties-conductivity, magnetism cost
Define Young’s Modulus
A measure of the stiffness of an elastic material
Define hardness
resistance to permanent deformation under a compressive load
Define ductility
ability to deform under tension
Define malleability
ability to deform under compression
Calculating the young’s modulus
Tensile stress/tensile strain
Define yield strength
max stress without permanent deformation
Define Ultimate Tensile Strength
max stress without failure
Identify thermal properties
thermal conductivity
thermal coefficient of expansion
strength/stiffness variation
Metals added to aluminium to improve properties
copper silicon magnesium zinc lithium
General properties of Aluminium
low-density high corrosion resistance electrical conductor easy to manufacture non-magnetic experiences fatigue limited temperature range
Define heat treatment
changing the structure of a material using heat to change mechanical properties
Define precipitation treatment
heat used to accelerate ageing to increase hardness and strength
Define solid solution treatment
Heat applied and then the material is rapidly cooled to allow alloying elements to be fully dispersed in the material
it leaves the material in a softened, temper state
it promotes natural ageing in some alloys
Properties of titanium
density = 4.5g/cm^3 60% heavier than aluminium but 2x stronger alloying elements = Al, zirconium, Si, Sn corrosion-resistant maintains strength at high temperatures high weight to cost ratio high specific strength low specific gravity
