Quiz 10: Chapter 11- Metal Casting

Relative to the size of the cast part in sand casting, the volumetric size of the pattern is which one of the following:

bigger than

Shell molding is best described by which one of the following:

casting process in which the mold is a thin shell of sand bonded by a thermosetting resin

results from splattering during pouring, causing the formation of solid globules of metal the become entrapped in the casting

cold shots

Occurs when two portions of the metal flow together but there is a lack of fusion between them due to premature freezing

cold shuts

For which one of the following reasons is a green mold named:

moisture is contained in the mold

a depression in the surface or an internal void the casting caused by a restriction in the amount of molten metal available to the last region of the cavity

shrinkage cavity

Given that Wm = weight of the molten metal displaced by a core and Wc = weight of the core, the buoyancy force tending to lift the core is which one of the following:

upward force = Wm-Wc

A gas cavity caused by the release of mold during pouring

Balloon

ability to give way and allowing a casting shrink without cracking the casting

Collapsibility

a network of small voids throughout the casting caused by localized solidification and shrinkage of the final molten metal in the dendritic structure

Microporosity

casting that solidify before completely filling the mold cavity

Misruns

a step in the cast product at parting line caused by relative displacement of cope and drag

Mold Shift

when fluidity of liquid metal is high, it may penetrate into the sand mold or core, causing surface to consist of a mixture of sand grains and metal

Penetration

to allow hot air and gases to pass through voids in sand

Permeability

formation of many small gas cavities at or slight below the surface of casting

Pin holes

Silica sand has which one of the following chemical compositions:

SiO2

To maintain shape and resist erosion

Strength

to resist cracking on contact with molten metal

Thermal stability

In casting, the term chaplet has multiple meanings. One use of the term refers to _____.

a support made of a metal having a higher melting temperature than the casting metal

In sand casting, the volumetric size of the pattern is____

bigger than

Cupolas are furnaces used to melt which one of the following metals:

cast iron

Which one of the following casting metals is most important commercially:

cast iron

An indirect fuel-fired furnace is an alternative name for which one of the following furnace types:

crucible furnace

Which one of the following expendable mold processes is known as a precision-casting process:

investment casting

In die casting, the term flash means _____.

liquid metal under high pressure squeezes into the small space between the die halves at the parting line

Investment casting is also known by which one of the following names:

lost-wax process

A misrun is which one of the following defects in casting:

metal solidifies before filling the cavity

What are the three main factors to successfully pouring molten metal?

pouring temperature, pouring rate and turbulence

Which one of the following casting processes is the most widely used:

sand casting

Which one of the following metals has the lowest melting point:

tin

A cupola is a vertical, cylindrical furnace equipped with a tapping spout near its base.

true

Which one of the following is the name of the casting process in which molten metal is poured into a rotating mold to produce a tubular part:

true centrifugal casting