industrial tests Flashcards
tensile industrial test
a tensometer machine
test piece is held in a clamp at each end
one clamp is fixed and the other moves on a worm drive gear mechanism, putting material under tension
test piece is stretched, the load and distance travelled is plotted, giving info on elastic limit, maximum load and final breaking point after ‘necking’
toughness industrial test
Izod impact test
notched test piece is held vertically in the vice of the machine
a pendulum is released from a set position and swings to strike the test piece
the energy absorbed by the test piece is calculated from the height the pendulum swings to after it hits the test piece
the material that absorbs the most impact is the toughest and gives the least pendulum swing
brittle material absorbs less energy and the pendulum swings further
malleability and ductility industrial test
using a bend test - withstands cracking
test piece placed into a bending machine and held, supported at the ends
mandrel or plunger loads the test piece at the centre and bends it to a predetermined angle or until the test piece fractures.
material then inspected
outer bend cracks indicate ductility
inner bend cracks indicate malleability
electrical conductivity industrial test
collect material samples of same dimensions
on top surface mark a set distance at each end
place a multimeter probe on each mark
measure the resistance
higher the resistance, lower the conductivity
thermal conductivity industrial test
use a heat flow meter
square shaped material test piece is placed between 2 temperature control plates
temperature is increased at a controlled rate
heat flow measures material by sensors placed on surface
as material is heated, the sensors measure and record rate of thermal conductivity
hardness industrial test
- rockwell test
- preload applied to material sample using a diamond indenter, breaks just the surface of the material
- diamond used as it doesn’t deform under load
- preload is the datum / zero reference position
- additional load is then applied to the test material and held for a pre determined length of time
- load is released and distance between the preload and applied load is measures
hardness industrial test
- brinell test
hardened standardised steel ball is forced into the materials surface using a pre-set load
diameter of indent measured
hardness industrial test
- vickers pyramid test
used for very hard materials
diamond square-based pyramid to indent the surface
microscope measures size of ident
hardness industrial test
- non destructive testing
on products rather than material samples
ultrasonic - sound waves pulsed into material, different sounds indicate faults
x-ray - beam passes through material and an image is projected on to a display screen, allowing the observation of tiny details such as hairline cracks within the material
