Materials & Processes Flashcards
(214 cards)
As hot working progresses (assuming the temperature of the part is held constant), the energy required for further processing:
a. increases.
b. decreases.
c. remain constant.
d. any of the above may be true, depending on the material.
a. increases.
A fatigue crack is a service defect that is caused by:
a. cyclic loading of the part above the yield strength of the material.
b. cyclic loading of the part below the yield strength of the material.
c. local overheating of the part.
d. corrosive atmosphere.
b. cyclic loading of the part below the yield strength of the material.
The middle portion of a molding flask is called a:
a. cope.
b. drag.
c. cheek.
d. separator.
c. cheek.
A cause of gas porosity in welds is:
a. welding at too low temperature.
b. improper cleaning or preheating.
c. the use of insufficient filler metal.
d. restriction of movement of the material.
b. improper cleaning or preheating.
In the resistance welding process:
a. two parts to be joined are heated then pressure is applied
b. the pieces to be joined are held firmly together under pressure, followed by the generation of heat at the interface.
c. no heat is applied and the parts are welded by applying pressure only.
d. the parts are heated but not melted and a filler metal is added.
b. the pieces to be joined are held firmly together under pressure, followed by the generation of heat at the interface.
In a mold, the runner connects:
a. the pouring basin to the sprue.
b. the downgate to the riser.
c. the sprue to the ingate.
d. the pouring basin to the mold cavity.
c. the sprue to the ingate.
Metal forming during rolling results in:
a. plastic flow of the metal.
b. elongation of existing defects perpendicular to the rolling direction.
c. directional properties which are always beneficial for secondary forming operations.
d. the flattening out of defects which makes them more easily detectable by most N.D.T. methods.
c. directional properties which are always beneficial for secondary forming operations.
A welding defect that occurs at the root and runs parallel with the weld is:
a. a lack of fusion between beads.
b. an icicle.
c. a crater crack.
d. a lack of penetration.
d. a lack of penetration.
Hot working an ingot may produce a product with:
a. fewer defects than in the original ingot.
b. more defects than in the original ingot.
c. the same number of defects as in the original ingot.
d. any of the above may be correct depending on the circumstances.
d. any of the above may be correct depending on the circumstances.
A disadvantage of dry sand molds when compared to green sand molds is that:
a. erosion of the mold is more common.
b. castings are more susceptible to hot tears.
c. a surface finish is generally worse.
d. the overall dimensional accuracy is worse.
a. erosion of the mold is more common.
A long defect, parallel to the longitudinal axis of a bar and caused by blowholes, cracks or tears introduced in earlier processing and elongated in the direction of rolling or forging is called a:
a. seam.
b. forging lap.
c. lamination.
d. cold shut.
a. seam.
Rapid oxidation of metal surfaces during hot working of a mild steel may:
a. produce a carburized surface layer.
b. produce a product which is thicker than originally intended.
c. adversely affect the cooling rate of the newly formed material.
d. adversely affect the application of some non-destructive tests.
d. adversely affect the application of some non-destructive tests.
An advantage of shell molding compared to green sand molding is:
a. that larger castings can be produced when using shell molds.
b. the lower cost of production of shell molding.
c. a better surface finish is obtainable.
d. All of the above.
c. a better surface finish is obtainable.
A burst is an/a _______________________ discontinuity.
a. inherent
b. processing
c. service
d. All of the above.
b. processing
Bursts usually have the following characteristics, they:
a. appear as smooth indentations on metal surfaces.
b. are cavities varying in size from wide open to very tight, usually parallel with the grain.
c. are extremely thin and flat, generally aligned parallel to the work surface of the material.
d. are three dimensional discontinuities having smooth internal surfaces and generally located close to the surface of the wrought material.
d. are three dimensional discontinuities having smooth internal surfaces and generally located close to the surface of the wrought material.
In a rolling mill, flattening and elongation of metal is accomplished primarily by:
a. tensile stresses.
b. bending stresses.
c. compressive stresses.
d. high frequency cyclic loads.
c. compressive stresses.
The fuel gas most commonly used in gas welding is:
a. Butane.
b. Propane
c. Acetylene.
d. All of the above.
c. Acetylene.
Cold shuts are most likely to be found in:
a. extrusions.
b. forging.
c. castings.
d. sintered parts.
c. castings.
Air craft turbine blades are usually processed by:
a. investment casting.
b. shell mold casting.
c. green sand casting.
d. dry sand casting.
a. investment casting.
The electrodes used for spot welding are usually made of:
a. Carbon.
b. Mild steel.
c. Tungsten.
d. Copper.
d. Copper.
A metal forming operation which allows three dimensional control over the shape of the product is:
a. Rolling.
b. Extruding.
c. Forging.
d. All of the above.
c. Forging.
A forming operation which results in the greatest dimensional accuracy is:
a. Cold rolling of sheet.
b. Hot rolling of sheet.
c. Cold rolling of bars.
d. Forging.
d. Forging.
In which of the following joining methods will flaws essentially be two dimensional?
a. Gas tungsten arc welding.
b. Gas metal arc welding.
c. Submerged arc welding.
d. Brazing.
d. Brazing.
A flaw which can resemble a cold shut is:
a. an undercut in a weld.
b. a hot tear in a casting.
c. a blowhole in a casting.
d. a forging lap.
d. a forging lap.