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34 Cards in this Set
- Front
- Back
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The specifications aircraft materials will list the tests which must be applied to a material to ensure that it is suitable for use in aircraft |
BS 4A |
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The state that occurs within a material when the said material is subjected to forces which tend to cause distortion? |
Stress |
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The most commonly used unit of stress is the? |
N/mm2 (stress tensile test) |
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1N/mm2, equals? |
1MN/m2 or 1MPa (stress tensile test) |
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1 bar =
1hbar = |
105 N/m2 or 105 MPa
107 N/m2 or 10 N/mm2
(stress tensile test)
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When a force is applied to a body which resists the force, some distortion |
Strain |
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Stress is directly proportional to? |
Strain |
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what is the formula for strain = |
Final Length - Original Length = Change in length (e) (Strain tensile test) |
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stress = |
a constant x strain (Strain tensile test) |
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This constant 'E' is known as Young’s Modulus of elasticity for the material |
E = stress (Strain Tensile test) |
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For steel, the constant ‘E’ is approximately? |
20,000 hectobar (or 200 kN/mm2) (Tensile test) |
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Thus a stress of 1 hbar will produce an extension or contraction of of the original length? |
1 20,000 (tensile test) |
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Tensile strength = |
maximum force used original area of cross section (tensile test) |
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The shape and dimensions of standard round and flat test pieces are |
BS 4A (Tensile test piece) |
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what are Extensometers used for? |
Used for measuring the extension over the gauge length of a test piece during a tensile test. Strains within the elastic limit are extremely small (tensile test piece) |
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When a metal is subjected to both tensile stress and high temperature over a long period, continuous and permanent tensile elongation takes place even if the stress is below the yield stress. what is this known as? |
‘creep’ (Tensile test piece) |
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the final fracture due to creep is known as? |
‘rupture’ (Tensile test piece) |
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What is the ‘limiting creep stress’ of a material? |
at any given temperature is the maximum stress it can withstand without showing any measurable extension. (Tensile test piece) |
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What is Hardness? |
resistance of a material to indentation (Hardness Tests) |
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What kind of test is this? |
Brinell Hardness test (Hardness Test) |
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BHN formula= |
Force (F) (Hardness test) |
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To make calculations unnecessary, the hardness number H is found by reference to? |
British Standard tables (Hardness Test) |
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What is the advantage off Vickers over Brinell? |
An advantage of the Vickers hardness test is that hardness values for very hard materials are more accurate than the corresponding Brinell numbers (Hardness Test) |
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What size is the diamond indentor angle at the head of the Vickers test? |
136° (Hardness test) |
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The specified time of contact between the indenter and the test piece in both Vickers and Brinell hardness tests? |
15 seconds (Hardness test) |
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The reading obtained during this test must be converted to what? |
Vickers Pyramid Hardness Number (VPN) (Hardness test) |
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In the Rockwell hardness test an indentation is made in the test piece using a diameter hardened steel ball or a diamond cone of ° |
1/l6in & 120° (hardness test) |
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What is the rockwell hardness test used mostly for? |
It is used mainly for the rapid routine testing of (Hardness Test) |
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This is a small portable instrument which can be used for testing the hardness of large components such as castings and gears? |
The Shore Scleroscope Hardness Test (Hardness Test) |
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What are impact tests used for? |
to indicate the toughness of a material and most (Impact tests) |
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What test does this test piece belong to?
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Izod test (Impact tests) |
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With the Izod test, The striking energy of the pendulum is approximatley? |
163J (Impact tests) |
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What test does this test piece belong to? |
Charpy Impact test (Impact test) |
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Progressive deterioration of the strength of a |
Fatigue |
