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Engineering Q2
Definition | Term |
---|---|
the ability of a material to resist wear, indentation and scratching eg, Glass | Hardness (Material Properties) |
The ability of a material to be stretched without fracture. A ductile material will be able to be drawn into wire eg. Copper | Ductility (Material Properties) |
The ability of a material to be extended in all directions without rupture. The malleability of a material increase with an increase in temperature. | Malleability (Material Properties) |
The ability of a material to withstand impact | Brittleness (Material Properties) |
The ability of a material to return to its original length when freed from a force distorting it eg. a spring | Elasticity (Material Properties) |
The ability of a material to be permanently deformed without fracture. The increases with heat. | Plasticity (Material Properties) |
The ability of a material to conduct heat ans electricity | Conductivity (Material Properties) |
Max load a piece can support divided by the cross sectional area. | Tensile strength (Material Properties) |
Load is directly proportional to the extension. Double the load and the extension doubles (straight line of the load extension graph) | Young's Modulus of elasticity (Material Properties) |
NDTs allow testing for quality yet will ensure that each acceptable component can be used. NDTs can be employed on each part part made The final product will not be destroyed in the testing process Cost effective over large number of parts | Non destructive testing |
Can be detected by eye or low powered magnifying glass | Macroscopic |
An optical microscope is used for this type of inspection | Microscopic |
This method is useful for finding surface cracks Fluorescent die is applied by spraying and it soaks into any surface flaws Clean off the excess Under UV light the flaw will be fluorescent along the crack and is easily seen | Penetrant Die test |
Theyre used for: Values for properties such as strength, ductility, toughness, elasticity, creep, etc can be ascertained Standardisation of components can be achieved Quality control is maintained The success of heat treatment can be measured | Destructive testing |
Done by pressing a hardened indenter into the piece. Brineli-Round ball(1,5,10mm) -soft material VIckers- square pyramid(136*)-Hard material | Hardness test |
The faiilure due to on/off loading or cyclic stressing. Failure begins as a minute crack. Sharp corners and poor surface finish can be some of the causes of metal fatique | Fatigue |
the slow deformation of a material over time resulting from a steady force acting on the material | Creep |
when a ductile material has a gradually increasing stress applied it behaves elastically up to a limiting stress. Deformation in the form of necking occurs. This fracture shows a cup and cone fracture | Ductile Fracture |
In brittle fractures failure occurs before any significant plastic deformation had occured. | Brittle Fracture |
Contains Iron | Ferrous |
Doesnt contain iron | Non-ferrous |
NON FERROUS metals A coil, energising with high frequency AC, is put close to a conductive material. A magnetic field is produced by currents. A defect with destort the magnetic field which will be located by search coil that displays the imperfection | Eddy current testing |
A striker/pendulum is released from a P determined height, . It strikes and breaks the piece. A pointer indicates the height of the follow through after breaking,thus determining the energy absorbed. | Impact testing |
Specimen held vertically, clamped at one end Notch facing the pendulum 167 Joules | IZOD impact test |
Specimen held horizontally, clamped at both ends Notch is on the opposite side of the pendulum 300 Joules | CHARPY impact test |
NDT; is a process for detecting surface and subsurface flaws in ferrous materials. Ferrous iron particles are applied to the part. if an area of flux leakage is present, the particles will attract to that area. | Magnetic particle test |
A probe is passed over the test specimen, sending high frequency vibrations which are reflected back on contact with the lower surface of the specimen. when a flaw is present, vibrations will reflect back from this point | Ultrasonic |
radiation from an x-ray tube. If no defects are present, the amount of absorption is uniform across the area exposed to the x-ray beam. If a defect is present,a smaller amount of rays is absorbed giving a variation in the intensity of the beam | Radiography testing |
Stress over strain | Young Modulus of elasticity |
Max Load over CSA | UTS |
Pie R squared | Cross sectional area (CSA) |
Load over CSA | Stress |
EXT over original length | Strain |