Metals Flashcards
______ employed for various engineering purposes and requirements
________ is the most popular metal in the field of engineering
ALL the metals have a _______
metals
iron
crystalline structure
________ is a mixture or compound of two or more elements, at least one of
which is metallic
______ enhances some properties, as required by engineering applications,
such as strength and hardness in comparison to pure metals
Classified into _________ and ________
An alloy
Alloying
solid solution and intermediate phase
__________
atoms of solvent element are
replaced in its unit cell by
dissolved element.
Substitutional solid solution
________ is an alloy in which one element is dissolved in another to form
a single-phase structure
In a solid solution, the solvent or base element is _______, and the dissolved
element can be either _________
Solid solutions can be __________ or ____________
Solid solution
metallic
metallic or nonmetal
Substitutional Solid Solution or Interstitial Solid Solution
_________ atoms
of dissolving element fit into
vacant spaces between base
metal atoms in the lattice
structure.
Interstitial solid solution -
There are usually limits to the solubility of one
element in another. When the amount of the dissolving element in the alloy
exceeds the solid solubility limit of the base metal, _________ fo______ is used to describe it because its
chemical composition is intermediate between the two pure elements. Its
crystalline structure is also different from those of the pure metals.
a second phase
intermediate phase
IMPORTANCE OF METALS
_________ – can be alloyed for high rigidity, strength, and
hardness
________ – capacity to absorb energy better than other classes of materials
________ – metals are conductors
___________ – conduct heat better than ceramics or polymers
____ – the price of steel is very competitive with other engineering materials
High stiffness and strength
Toughness
Good electrical conductivity
Good thermal conductivity
Cost
METALS USED IN MANUFACTURING PROCESS
_______ - starting form is a casting
_________ - the metal has been worked or can be worked
after casting
_________ - starting form is very small powders for
conversion into parts using powder metallurgy techniques
Cast Metal
Wrought Metal
Powdered Metal
CLASSIFICATION OF METALS
___________
These metals contain iron as main constituent
are classified as cast iron, wrought iron, and steel depending
upon ingredients and percentage of carbon content
____________
These metals practically do not contain iron
FERROUS METALS
NON-FERROUS METALS
_______ contains a higher percentage of carbon ranging from _______
________ is manufactured by melting of pig Its properties
1. It can be hardened by heating and sudden cooling, but it cannot be tempered.
2. It does not rust easily.
3. It is fusible.
4. It is hard and at the same time brittle.
Cast Iron
2 to 4.23
Cast Iron
CUPOLA.
Cast Iron (C.I.) Classification
1. ___________ - The carbon content is about ____ ad when fractured gives a
grey appearance. It is soft and readily melts. Its strength is weak and is used
for casting cylinders, pistons, manholes etc.
2. _________ - Its carbon content is ______. It contains carbon in
chemical form and on fracturing gives silver white luster. It is hard, not
workable on machines and is used for preparing pump liners, drawing dies
etc.,
3. ___________ its carbon content is 3.3%. It is produced by casting the
molten metal against a metal chiller to obtain a surface of white cast iron.
This is hard to a certain depth from the outer surface, which indicates the
white iron. The inner portion of the body is made up of grey iron which is soft.
It is used for manufacturing rail car wheels, dies, sprockets etc.
Grey Cast Iron
3%
White Cast Iron
2.0 to 2.5%.
Chilled Cast Iron
- ___________- Its carbon content is __. The composition of this is
so adjusted that it becomes malleable. It is done by extracting a portion of
carbon from cast iron. It has high field strength and used for manufacture of
automobile and railway equipment such as rail cars, crank shafts gear boxes
etc. - _________- It is obtained by melting cast-iron with wrought iron
scrap. The proportion of wrought-iron scrap is about _________ of cast-iron.
Malleable Cast Iron
2.3%
Toughened Cast Iron
1/4 to 1/7th
It is an almost pure iron. Its carbon content is 0.15%
Stages
_____________________
Properties
1. It is _____ at white stage of heat. It can be easily forged and welded.
2. It is ductile, malleable and tough.
3. Its melting point is ________
4. It is resistant to ________.
Wrought Iron
Refining-Puddling-Shingling-Rolling
soft
1500°C.
corrosion
__________ is defined as the iron alloy with a carbon content of up to ____%.
Types of steel include low carbon steel or mild steel, medium carbon
steel, and high carbon steel.
Steel
2.0
__________ 0.10 to 0.3% It can be easily hardened and
tempered
It is malleable and ductile
It can be forged and welded
It rusts easily
Specific gravity is ___
Sheets, Tin Plates
Low Carbon or Mild
7.8
________ 0.3 to 0.6% These steels have high strength,
toughness, hardness and stiffness
Boiler plates, Railway
tyres, pressing dies
Medium Carbon
________ 0.6 to 1.50% It can be easily hammered and tempered
Specific gravity is ___
It can be magnetize permanently
It is granular in structure
Springs, Hammers,
Drills, Chisel
High Carbon
7.9
Steel, to which elements other than carbon are added in sufficient quantity, in
order to obtain special properties, is known as _______.
Examples of alloy steels include chromium steel, cobalt steel, manganese steel,
tungsten steel, vanadium steel and Nickel steel.
Alloy Steel
__________ - Chromium up to ____
Vanadium up to _____
Highly ductile, can be easily
worked and welded
Used for locomotive springs,
pistons and bolts
Chromium Steel
0.9%,
0.15%
__________ Cobalt is added to high
carbon steel
Possesses magnetic
properties
Used for making permanent
magnet with strong
magnetic field
Cobalt Steel
__________ Manganese up to _____ It is hard, strong and ductile.
It gives resistance to
abrasion.
Used for gears
Manganese Steel
1.90%
_________
Tungsten content up to _____ It is hard and maintains
cutting power at high
temperature
Used for lathe tools, drill
cutters
Tungsten Steel
or High Speed
Steel
7%
________ Nickel up to ____ It is hard and ductile Used for boiler plates,
structural steel propeller
shafts
Nickel Steel
3.5%
________ Vanadium content up to
0.2%
Strong and ductile, elastic
limit is high, resists shocks
Used for automobile parts,
springs
Vanadium Steel
NON-FERROUS METALS
_________
It is a very light and useful non-ferrous
metal. It is produced mainly from bauxite
which is hydrated oxide of aluminum.
Properties
1. a tin white metal.
2. good conductor of heat and electricity.
3. malleable, ductile and very light.
4. highly electro positive element.
Uses
1. For manufacturing of electrical conductors.
2. Making alloys.
3. For manufacture of cooking utensils,
surgical instruments, etc.
4. For making parts of air crafts.
5. In manufacture of paints
Aluminum
_____ is one of the most useful non-ferrous
metals. It occurs in nature in a free state as
well as combined state.
Properties
1. Bright shining metal of reddish color.
2. high tensile strength.
3. very malleable and ductile.
4. a good conductor of heat and electricity.
5. It melts at 1083°C
Uses
1. For the manufacture of electrical cables
and wires and lightning conductors.
2. For making alloys.
3. For house hold utensils.
4. For bolts and nuts.
5. For tubes, etc.
Copper
NON-FERROUS METALS
___ is a very important non-ferrous metal
which is obtained from ore, tin pyrites or
tinstone.
Properties
1. When a bar of tin is bent, a peculiar noise
takes place which is known as a cry of tin.
2. white metal with brilliant luster.
3. soft and malleable.
4. withstands corrosion due to acids.
5. melts at 232°C.
Uses
1. Used for plating.
2. For lining and lead pipes.
3. For making alloys and solders.
4. For making trunks, boxes, cans, pans, etc.
Tin
____ is one of the most extensively used non-
ferrous metals. Occurs in wide variety of
combination in nature. It is manufactured
from ores by roasting and subsequent
distillation with carbon.
Properties
1. bluish white metal.
2. easily fused.
3. brittle when cold, but malleable at a high
temperature.
4. can be rolled into sheets.
5. melting point is 420°C
Uses
1. Used for galvanizing steel sheets.
2. For making roofing sheets, pipes,
ventilators.
3. Used in brass making.
4. For making negative poles of batteries.
Zinc
NON-FERROUS METALS
_____ is extracted from galvena ores. It is a very
cheap, but useful nonferrous metal. It is
produced from the ores by smelting in a
reverberatory furnace.
- very soft, heavy blush grey in color.
- can be easily cut with a knife.
- makes impression on paper.
- melting point is 327° and boiling point is
1600°C.
Uses of Lead - For making shots and bullets.
- Used for making gas pipes.
- Printers type letters.
- Flushing tank.
- Roof covers.
Lead
SUPER ALLOYS
Three Groups of Superalloys
1. _________ in some cases iron is less than 50% of total composition
2. _________ - better high temperature strength than alloy steels
3. _________ - ~ 40% Co and ~ 20% chromium
Iron-based alloys
Nickel-based alloys
Cobalt-based alloys
SUPER ALLOYS
Importance:
Room temperature strength properties are good in comparison to other metals, but
not _______
High temperature performance is _________ – tensile strength, hot hardness, creep
resistance, and corrosion resistance at very elevated temperatures
Operating temperatures often in the vicinity of _________
Have many applications
Example is that it is used in systems in which operating efficiency increases with
higher temperatures e.g., gas turbines, jet and rocket engines, steam turbines,
and nuclear power plants
outstanding
excellent
1100°C (2000°F)
_____________
processing of metals should be carried out carefully
Affects the mechanical properties of metals
Grain Size Effect
Grains in metals tend to grow ______ as the metal is heated
metals with small grains are ______ but they are less ductile
METAL PROCESSING
larger
stronger
______________
Most steels may be hardened by heating and cooling rapidly
metals are ________ in water or oil
Produce very hard but brittle metal
____________
a softening process in which metals are heated and then allowed to cool slowly
____________
heating a hardened metal and allowing it to cool slowly
produce a metal that is still hard and less brittle
results formation of small Fe3C (iron carbide or cementite) precipitates in the steel, which provides strength
Quenching and Hardening
Annealing
Tempering
____________
refers to the process of strengthening a metal by changing its shape without
the use of heat
also known as plastic deformation or work hardening, involves strengthening
a metal by changing its shape.
the metal is subjected to mechanical stress so as to cause a permanent
change to the metal’s crystalline structure___
Cold Working
METAL MANUFACTURING: PRODUCTION
___________
_________ - molten metal is poured into a mold cavity where, the metal take on the
shape of the cavity once it cools
For small intricate parts (Dies, jewelry, plaques, and machine components )
SHOULD ____ be used for products that require high strength, high ductility, or tight
tolerances
a. __________ - the mold must be destroyed in order to remove the part
b. _________ - the mold is fabricated out of a ductile material and can be
used repeatedly.
CASTING
Melting and molding
NOT
Expendable Mold Casting
Permanent Mold Casting
METAL MANUFACTURING: PRODUCTION
_____________
treats powdered metals with pressure (pressing) and heat (sintering) to form different
shapes
______________ is known for its precision and output
quality – it keeps tight tolerances and often requires no secondary fabrications
__________ is compacted into the desired shape and heated to cause the particles to
bond into a rigid mass.
incredibly costly and generally only used for small, complex parts
Powder processing is _____ appropriate for high-strength applications.
Powder Processing
Powdered metallurgy (processing of powdered metals)
metal powder
NOT
METAL MANUFACTURING: PRODUCTION
_______
______ (usually in sheet metal form) is mechanically manipulated into a desired shape
Unlike casting, metal forming allows for higher strength, ductility, and workability for additional
fabrications
Forming
raw metal
METAL MANUFACTURING: FABRICATION
_________
bending, rolling, forging, and drawing
include metal forming and sheet metalworking
Application of stresses to the piece which exceed the yield stress of the metal
There are two types
a._________ - characterized by large deformations and shape changes
surface area to volume ratio is relatively small
include rolling, forging, extrusion and wire and bar drawing.
b. __________ - performed on metal sheets, strips and coils having a high surface area
to volume ratio.
use a punch and die to form the workpiece
Bending, drawing and shearing
Deformation
Bulk Processes
Sheet Metalworking
METAL MANUFACTURING: FABRICATION
________
any fabrication method that removes a section of the metal
also known as material removal processing
Cutting, shearing, punching, and stamping are all common types
a._____________ - These are cutting operations using cutting tools that are harder than the
metal of the product. They include turning, drilling, milling, shaping, planning, broaching and sawing.
b. _________ - In these methods material is removed by abrasive particles that normally form
a bonded wheel. Grinding, honing and lapping are included in this category.
c. __________ - These methods use lasers, electron beams, chemical erosion, electric
discharge and electrochemical energy instead of traditional cutting and grinding tools
When planning for machining in your supply chain, hardening processes should happen AFTER
machining processes. Hardened metals have a high shear strength and are more difficult to cut.
Machining
Machining Operations
Abrasive Machining
Nontraditional Processes
METAL MANUFACTURING: FABRICATION
________
one of the last steps of the metal manufacturing process
includes welding, brazing, bolting, and adhesives.
Assembly can be done by machine or by hand, where multiple parts are connected either
permanently or semi-permanently to form a new entity.
_________
includes everything from galvanization to powder coating, and can take place throughout the
manufacturing process
Joining
Finishing
MECHANICAL PROPERTIES OF MATERIALS
__________
It is the capacity of the material to withstand the breaking, bowing, or deforming under the action of
mechanical loads on it.
_________
It is the property of a material to come back to its original size and shape even after the load stops acting on it.
___________
It is the property of a material that makes it to be in the deformed size and shape even after the load stops
acting on it.
_________
It is the property of a material that allows it to deform or make into thin wires under the action of tensile loads
plastically.
__________
It is the property of a material that allows it to deform under tensile loading without breaking under the action
of a load
Strength
Elasticity
Plasticity
Ductility
Tensile strength
the strength of a material per unit material or unit strength
Stress
_________
either tensile stress or compressive stress
Tension or tensile force applied results to
Tensile Stress (______)
Compression or compressive force applied
results to Compressive Stress (__________)
NORMAL STRESS
STRESS-STRAIN DIAGRAM
__________
The maximum ordinate in the stress-str
diagram is
__________
the strength of the material
at rupture. This is also known as the breaking
strength
Ultimate Strength
Rapture Strength
STRENGTH OF MATERIALS
STRESS-STRAIN DIAGRAM
___________
limit beyond which the material will no longer
go back to its original shape when the load is
removed
___________
The region in stress-strain diagram from O to P
is called the _______. The region from P to
R is called the _______
_________ the point at which the material will
have an appreciable elongation or yielding
without any increase in load
Elastic Limit (E)
Elastic and Plastic Ranges
Yield Point
Yield point
__________
the graph of quantities with the stress σ along
the y-axis and the strain ε
differs in form for various materials
Metallic engineering materials are classified as
either ________
__________is one having relatively
large tensile strains up to the point of
rupture like structural steel and aluminum
_________ have a relatively small
strain up to the point of rupture like cast iron
and concrete.
STRESS-STRAIN DIAGRAM
ductile or brittle
Ductile material
Brittle materials
__________ results from forces applied parallel to the area of the resisting force
________ contact pressure between separate bodies
differs from compressive stress, as it is an internal stress caused by compressive forces
shearing stress
Bearing Stress
__________ also known as unit deformation,
the ratio of change in length caused by applied force to the original strength
Dimensionless
simple strain
_________
the graph of quantities with the stress σ along
the y-axis and the strain ε
differs in form for various materials
Metallic engineering materials are classified as
either ______
_______ is one having relatively
large tensile strains up to the point of
rupture like structural steel and aluminum
________ have a relatively small
strain up to the point of rupture like cast iron
and concrete.
STRESS-STRAIN DIAGRAM
ductile or brittle
Ductile material
Brittle materials
stress is directly proportional to strain
Proportional Law, Hooke’s Law
the proportionality k is called ____________ and is equal to the slope of the stress strain diagram from O to P
Modulus of Elasticity E or Young’s Modulus
STRESS-STRAIN DIAGRAM
_____________
limit beyond which the material will no longer
go back to its original shape when the load is
removed
Elastic and Plastic Ranges
The region in stress-strain diagram from O to P is called the _________. The region from P to
R is called the ________
Yield Point
_________ is the point at which the material will
have an appreciable elongation or yielding
without any increase in load
Elastic Limit (E)
elastic range
plastic range
Yield point
________
The maximum ordinate in the stress-strain
diagram is the ultimate strength or tensile
strength
Rapture strength is the strength of the material
at rupture. This is also known as the breaking
strength
Ultimate Strength
Rapture Strength
