Materials Flashcards
metal such as,——–,———-,———– can be in their pure form and when they are known as Metallic elements?
1.gold
2.sliver
3.copper
4.aluminum
when a metal contains a combination of two or more metals,it is then considered an ———?
alloy.
expanded metal it can be used ?
for security purposes, saftey guards for moving parts on equipment and machinery.
what is commonly used in the sheet metal trade for sound attenuation.
perforated metal.
perforated metal the holes can be ?
round , square, hexagonal, oblong, and many others.
hardware cloth or bird screen it comes some common sizes is ?
1/4’’ by 1/4
1/2’’ by 1/2’’
1’’ by1’’
hardware cloth used for?
extensively to cover openings of hoods and vents prevent the entry of unwanted pests.
what is brittleness?
is in a metal is the ability to withstand distortion.
materials such as glass, cast, iron, and very hard steel [files] are considered?
brittle.
conductivity may refer to either ?
heat conductivity or electrical conductivity.
what is an excellent conductor of both heat and electricity and used extensively as a cable in electrical systems?
copper.
what is the ability to withstand stretching ,bending orn twisting past ?
ductile.
what is elasticity?
the tendency of metal to return to it’s original shape after forces have caused the metal to become deformed.
what is the ability to withstand mechanical processing such as rolling , forging and hammering without cracking or braking ?
mealleable
what is strength ?
is the amount of high ,steady stress a metal can withstand before it yields.
What is toughness?
Is the ability of a metal to withstand an impact load.
Example of tough metal?
Titanium.
What is the combination of operations involving the heating and cooling of metal?
Heat treatment.
Heat treatment falls into three categories?
Annealing
Quenching
Tempering
Annealing is
A process used to release internal stresses in hardened metal.
What is that cooling of metal that is heated by immersion in a medium such us water and oil ?
Quenching
Tempering is ?
The increasing the toughness and decreasing hardness.
Practically all the work that is done to metal in shop is ?
Cold work.
What is the result of when the metal is exposed to the oxygen in the atmosphere?
Oxidation.
Stainless steels have the addition of ?
Chromium.
What is a corresive process that results when dissimilar metals come in contact with an electrolyte such as moisture?
Galvanic action.
One way to prevent this galvanic action from happening is to provide a barrier between the two metals such barriers include?
Strips of lead between the metal
Heavy tinning of the ferrous metal
Good quality
Heavy coat.
Ferrous metal or metal using?
The us standard gauge.
Non ferrous also known as the brown sharpe using?
American standard wire gauge.
Metals are broken into two basic groups?
Ferrous and Non ferrous.
Steel is an alloy primarily composed of iron with a carbon content between——— and———— by weight depending on the grade?
0.02 percent and
1.7 percent.
Black iron may?
Either hot rolled or cold rolled.
Black iron that measures more than 1/8” is called?
Steel plate.
When welding zinc coated sheets, ventilation of the zinc oxide fumes is crucial to prevent an illness known as?
The zinc chills or metal fume fever.
Another disadvantage of zinc coated metal is not to used on any food ?
Because the zinc and its compounds are poisonous.
What are produced by electroplating zinc onto steel in continuous process?
Electrogalvanizing
Steel sheets that have zinc added to them electrogalvanzing go by the trade name of ?
Satincoat
Paintlock And
Wipecoat.
26 gauge sheets of galvanized iron will be thicker than a 26 gauge sheet of black iron?
True or false
True
Gal alime is zinc aluminum alloy coating with superior corrosion resistance used for?
The outer wall B- vent an L-vent chimney and fittings.
One of the most common types of stainless steel used in the sheet metal trade is ?
304 of the basic 18-8 group which contains 18’/‘ chromium, 8 percent nickel,0.08 percent carbon (max) and the rest of steel
Stainless steel comes in various finishes?
1 finish - where finish is not important.
2d finish a dull finish.
2B finish plan finish.
4 finish a stain finish on one side used restaurant, kitchen.
When working with stainless steel?
All work areas should be iron free to prevent contamination and possible corrosion of the metal.
Non ferrous metal consists elements are ?
Copper, and aluminum or alloys such as brass.
Aluminum is obtained from an ore called?
Bauxite , which is found mainly the tropics and sub tropics with some deposits in Europe
Aluminum is lightweight weighing about ?
One theird the weight of steel.
To avoid fracturing,aluminum should be bent using a bend radius of ?
3 times the material thickness.
Aluminum has many uses?
Automotive
Aerospace and
Marine industries.
Aluminum is gauged in ?
Decimal parts of an inch or the brown and sharpe gauge.
What is reddish brown metal that is considered an element?
Copper
What is the advantage of copper?
Excellent conductor of heat and electricity.
When copper oxidizes it forms a greenish coating that is called?
Patina
Copper is gauged by weight in ?
Ounces per square foot.
Brass is?
The common name used for all copper zinc alloys.
What is the advantage of brasses?
Are highly malleable and are easily cast ,forged, rolled and pressed.
There are two basic categories of plastics?
Thermosetting and
Thermoplastic.
