Chapter 6 Flashcards
METALS
What are some of the properties that distinguish metals from ceramics and polymers
metals have: high strength and stifmess, good electrical and thermal conductivity and higher density than ceramics or plymers
What are two major groups of metals
ferrous and non ferrous
What is an alloy
metal that has two or more elements (one of them is metallic)
what is a solid solution in the context of alloys
alloy in whihc one of the metallinc elements is dissolved in another to form a single phase
Distingush between a substitutioal solid solution and an interstitial solid solution
Substitutional solid: atoms of the dissolved elemnt replace atoms of the solution elements in the lattice structure. An interstitioal solid solution has extra atomsWhat
is an intermediat phase
When the solubility limit of the base metal is exceeded (there is too much solute in the solution so a part of it is not dissolved)
The copper nickel system is a simple alloy system as indicated by a phase diagram, whiyis it so simple
because it is a solid solutionalloy throught its entire composition range
What is the range of carbon percentages which defines an iron-carbon alloy as steel
0,02% to 2.11%
What is the range of carbon percentafe which defines iron-carbon alloy as cast iron
2.11 to 5%
Common alloying elements for steel
Ce Mn Mo, Ni and V
What are some of the mechanisms byw which the alloying elements other than carbon strengthens steel
by solid solution alloying. Cr, Mn, Mo and Ni increase hardenability during heat treatment, CR and MO improve hot hardness, (Cr, Mo, V) form hard carbides with C which increases water resistance, Vanadiun inhibits grain growth
What is the predominant alloying element in all of the stainless steels
Chromium
Why is austentic stainles steel called that way?
Because this alloy exists in its austentinc phase at room temperature (FCC)
Besides high carbon content, what other element is characteristic of cast irons
siliconi
dentify some of the porperties for which aluminum is noted
low density, hgih electrical 6 thermal coductivity, good corrosion resistance, ability to be alloyed to achieve good strength to weight ratios
What are some noeteworthy properties of magnesium
lowest density, propensity to oxideze, low strength. Can be alloyed and strengthened to achieve goos strength to weight ratios
Most important engineering property of copper
high electrical & thermal conoductivity
What elements are alloyed with copper to form bronze and brass
tin and zing
important applications of nickel
alloying ingredient in steel, plating of steel to resist corrosion, nicklel based alloys for temp. performance
titanium properties
high strength-to-wight ratio, corrotion resistance, hgigh temp.strength
applications of zing:
easy to cast, coating inb galvanized steel, alloyingelement with copper to form brass
alloy by lead and tin
solder
name reefractory emtsals
CV, Mo, Ta, W. REfraactory emeans capacit tio withstand high temp. serice
Noble metals, why
platinum, silve,r gold, copper. They are chenically incactive
Superalloys divide into three gorups. name
iron based, nickel, cobalt based
why superalloys special
strength, resistance to corrosion and oxidation at high temp.
basic methods by which metals can be strengthened
alloyoing to form solutions and two-phase structures, 2 cold working . strain hardened metal is harder . 3 heat treatment, increase strength of metal
Which are inconsistent with metals (two correct) (a) good thermal conductivity, (b) high strength, (c) high electrical resistivity, (d) high
stiffness, and (e) ionic bonding?
c electrical rsistivity and e ionic bondig
Which of the folowing is most abundand to earth (a) aluminum, (b) copper, (c)
iron, (d) magnesium, or (e) silicon?
a aluminum
Predominant phase in the iron carbon alloy for a composition of 99&Fe at room temperature is which of the following (a) austenite, (b) cementite, (c) delta, (d) ferrite, or (e)
gamma?
d ferrite
steel with 1& cabon is known as which of the following (a) eutectoid, (b) hypoeutectoid,
(c) hypereutectoid, or (d) wrought iron?
c hypereutectoid
The strength of steel increases as carbon
increases
Plain cargon steels are designated in the AISI CODE SYSTEM BY : (a) 01XX, (b)
10XX, (c) 11XX, (d) 12XX, or (e) 30XX?
b 10XX
which of the followign elements is the most importantalloying element in steel (a) carbon, (b)
chromium, (c) nickel, (d) molybdenum, or (e) vanadium?
a carbon
Which of the following is not a common alloy in steel (a) chromium, (b)
manganese, (c) nickel, (d) vanadium, (e) zinc?
e zinc
Solid solution alloying is the principal strengtheinign mechanism in high strength low-alloy steels true false
true
Which of teh followingis the most important in cast iron commercially (a) ductile cast iron, (b) gray
cast iron, (c) malleable iron, or (d) white cast iron?
b gray cast alloy
Which of the following metals ahs the lowest density (a) aluminum, (b) magnesium, (c) tin, or
(d) titanium.?
b magnisium
Which of the following metals has the highest density (a) gold, (b) lead, (c) platinum, (d) silver, or
(e) tungsten?
c platinum
From which of thhe followingore is aluminun derived a) alumina, (b) bauxite, (c) cementite, (d)
hematite, or (e) scheelite?
b bauxite
Which of the follwoing metals is noted for good electrical conductivity (a)
copper, (b) gold, (c) iron, (d) nickel, or (e) tungsten?
a Copper
Traditional brass is an alloy of which of the followingmetallic elements : (a)
aluminum, (b) copper, (c) gold, (d) tin, and (e) zinc?
b copper, e zinc
Whcih of the follwoing metals has the lowest melting point a) aluminum, (b) lead, (c)
magnesium, (d) tin, or (e) zinc?
d tin
