Term
| Explain compressive strength |
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Definition
| Compressive strength is a measure of a materials ability to resist deformation when under a compressive stress. These stresses tend to cause a material to shorten and thicken between the stress impact points. |
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Term
| What happens to a metal when compressive stress is applied uniformly at all points of that metal's surface |
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Definition
| the metal will grow smaller (more dense) |
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Term
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Definition
| The measure of a material's ability to resist deformation in a plastic manner. |
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Term
| What happens once a material passes its "Yield Point" |
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Definition
| its deformation will no longer be in an elastic manner, instead it will start to deform in a plastic manner. As stress is increased it will continue to undergo plastic deformation until the material fails. |
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Term
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Definition
| the measure of how much tension load a material can withstand before breaking |
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Term
| plastic deformation has what kind of an effect on tensile strength? |
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Definition
| No effect. The tensile strength is independent of plastic deformation. |
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Term
| A material's Yield Point is 2000 lbs. of force, and you apply 2200 lbs of force and cause it to deform in a plastic manner. After that, you apply 2000 lbs of force to the material. Will the material deform in a plastic manner? If not, why? |
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Definition
| No, because when you first exceeded the yield point, the material adopted a new yield point at the higher force. Now the material will no longer undergo plastic deformation until you exert a force on it greater than the new yield point. |
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Term
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Definition
| a structure that consists of an atom in each corner of a crystal cube and an atom in the center of each face of the cube. |
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Term
| Name examples of Face Centered Cubic crystals in normal ambient conditions |
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Definition
| Copper, aluminum, silver, gold, nickel, lead, and platinum. |
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Term
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Definition
| Structure that consists of an atom in each corner of a crystal cube and an atom in the center of the cube. |
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Term
| Name examples of Body Centered Cubic crystals in normal ambient conditions |
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Definition
| Iron, chromium, molybdenum, vanadium and tungsten. |
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Term
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Definition
| Three layered structure consisting of seven atoms in both the upper and lower layer and three atoms in the middle or center layer |
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Term
| Name examples of Close Packed Hexagonal crystals in normal ambient conditions |
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Definition
| magnesium, zinc, titanium, cadmium and beryilium |
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Term
| Explain why torque limits are developed for materials. |
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Definition
| Torque limits are established to prevent failures due to torsional stress. In most instances these limits are established low enough to prevent plastic deformation of the material. |
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Term
| List the mechanisms required for brittle fracture of ductile materials |
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Definition
-Atomic structure susceptible to brittle fracture such as BCC
-A flaw or defect in the material
-Critical stress amount
-Low temperature, sufficiently low enough to change the response characteristics of the material |
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Term
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Definition
| the process of making a normally ductile material brittle. |
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Term
| List the causes of embrittlement on a metal |
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Definition
| Temperature, cyclic stress, radiation, environment |
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Term
| What kind of stress does heat-up or cooldown impart on a substance? |
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Definition
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Term
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Definition
| The minimum length of time that must elapse between two ionizing events occurring in the counter, such that they are distinguished by the counter as two events instead of one |
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Term
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Definition
| the minimum time that must elapses from the moment of detection of a first event until the electronics are able to detect a second event |
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Term
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Definition
| If two particles enter th4e counter in rapid succession, the avalanche of ions from the first particle renders the detector incapable of responding to the second particle |
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Term
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Definition
| The time from which the detector is able to produce a second pulse that is less than full size until a full size pulse is able to be produced |
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Term
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Definition
| Field produced by the applied voltage is not strong enough to collect all ions, so some ion pairs recombine before reaching the anode and cathode. the resulting current does not represent the radiation present |
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Term
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Definition
| The resulting current is proportional to the amount of energy deposited in the detector, the current remains constant for an increasing voltage |
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Term
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Definition
| The ions gain enough velocity/energy to cause secondary ion pairs to be formed, the amount of amplification is dependent on the amount of voltage applied, these detectors are more sensitive than ion chambers |
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Term
| Limited Proportional Region |
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Definition
| Gas amplification is no longer proportional to the type of radiation or incident energy due to low mobility of positive ions causing reduction in electric field strength, since amplification is not constant, the magnitude of an increase in the radiation field strength is difficult to determine |
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Term
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Definition
| the current increases slightly with voltage, the tube becomes flooded with ions traveling toward the anode and cathode, flooding the tube results in a current that is independent of the initial energy or type of radiation causing the initial ion pairs to be formed. A current pulse is generated for each event however a second event would go undetected until the ion flood is dissipated, Its the most sensitive region of the curve |
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Term
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Definition
| The applied voltage is large enough to strip electrons from the gas atoms with no radiation present, the voltage incerease can result in arcing of the current across the detector, use of this region will result in damage to the dector in a very short period of time. |
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