Chapter 11 Processing of metal alloys Flashcards
what are the two classifications of metal alloys
what are the two classifications of metal alloys?
- Ferrous
- Nonferrous
define Ferrous and nonferrous alloys
Ferrous - refers to various alloys of iron with a high proportion of one or more other elements such as manganese, aluminum, or silicon. They are used in the production of steels and alloys
nonferrous - metals or alloys are materials that are not iron-based
in steels what are the three types of of low alloys
low carbon
med carbon
high carbon
what is a blast furnace
is a type of metallurgical furnace used for smelting to produce industrial metals,
2 examples of iron-based alloys
steels and cast irons
describe cast irons
cast iron is a group of iron-carbon alloys with a carbon content more than 2%
Fe-c true equilibrium diagram
what are the 5 types of cast iron
what are the 5 types of cast iron
gray iron, ductile iron, white iron, malleable iron, compacted graphite iron
Grey iron properties
ductile iron properties
white iron properties
malleable iron properties
compacted graphite iron properties
* quick reference on the production of cast irons *
3 limitations of ferrous alloys
1) relatively high densities
2) relatively low electrical conductivity
3) relatively poor corrosion resistance
6 different types of nonferrous alloys
Cooper Aluminum Titanium Magnesium noble metals and refractory metals
what are noble metals
a metal (e.g. gold, silver, or platinum) that resists chemical action, does not corrode, and is not easily attacked by acids.
what are refractory metals
are a class of metals that are extraordinarily resistant to heat and wear.
ex tungsten
2 ways to fabricate metal
- blacksmith
- cast molten metal into a mold
in metal fabrication what are some differences
hot working vs cold working
hot working - deformation temperature high enough for recrystallization, large deformations
cold working - deformation below the recrystallization temperature, strain hardening occurs, small deformations
3 methods of fabricating metal
- forming
- casting
- miscellaneous
4 types of forming fabrication
what is casting in the metal fabrication process
what is sand casting
what is investment casting
a technique for making small, accurate castings in refractory alloys using a mold formed around a pattern of wax or similar material which is then removed by melting.
define die casting and continuous casting
die casting - is a metal casting process that is characterized by forcing molten metal under high pressure into a mold cavity
continuous casting - also called strand casting, is the process whereby molten metal is solidified into a “semifinished” billet, bloom, or slab for subsequent rolling in the finishing mills.
in metal fabrication what 2 different types of miscellaneous
powder metallurgy - is a term covering a wide range of ways in which materials or components are made from metal powders.
welding - is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion
5 types of annealing
stress relief
full anneal
normalize
spheroidize
process anneal
define annealing
heat (metal or glass) and allow it to cool slowly, in order to remove internal stresses and toughen it.
stress relief annealing
Reduce
stresses resulting from:
- plastic deformation
- nonuniform cooling
- phase transform.
Spoheroidize annealing
Spheroidize (steels):
Make very soft steel for
good machining. Heat just below Teutectoid
& hold for 15-25h.
full annealing
Make soft steels for good forming. Heat to get y, then furnace-cool
to obtain coarse pearlite.
process annealing
Negate effects of cold working by (recovery/recrystallization)
normalize annealing
Normalize (steels): Deform steel with large grains. Then heat-treat to allow recrystallization and formation of smaller grains.
quenching
is the rapid cooling of a workpiece in water, oil, or air to obtain certain material properties.
heat treatment temperature-time paths
what is hardenability
is the depth to which a material is hardened after putting it through a heat-treatment process. It should not be confused with hardness, which is a measure of a sample’s resistance to indentation or scratching
the reason why hardness changes with distance
influences of quenching medium and specimen geometry
what is a precipitation hardening?
also called age hardening or particle hardening is a heat treatment technique used to increase the yield strength of malleable materials, including most structural alloys of aluminum, magnesium, nickel, titanium, and some steels and stainless steels
