Metallic Materials Flashcards
What is a Metallic Bond?
– bond with one, two, or three valence electrons
– Non-directional bond valence electrons free to drift through the entire material forming a “sea of electrons” surrounding net positive ionic cores
– non-directional bond
Properties of metallics
– good conductors of electricity and heat
– shiny appearance
– susceptible to corrosion
– strong, but deformable
What do Ferrous alloys contain?
They contain Iron (Ferrous) as base metal
– Magnetic
What do Non-Ferrous alloys contain?
materials and alloys based on other metals
– non-magnetic
What materials are used to create Iron
Iron Ore, Limestone, Cocaine (Coke)
In what state is Iron found?
– Iron not found in ‘free state’ and must be found in rocks and oxides, hence Iron ore
How is iron separated from its ore?
The ore is crushed
and the iron is separated then
made into pellets, balls or briquettes using binders, such as water.
The pellets are typically 65% iron, and about 1” in diameter.
How is coke formed
Coke is formed by heating coal to 1150°C, then cooling it in quenching towers
Like injecting cocaine, it must be heated first before shooting up
What is the purpose of coke?
Used as fuel. Generates high heat needed in order for chemical reactions in ironmaking to take place
Similar to taking cocaine which would increase your energy levels and make you feel wide-awake
What does coke produce?
Produces carbon monoxide (CO)
& reduces the iron-oxide to iron
Like the effects of carbon monoxide on humans, cocaine can cause death as a result of overdose
Don’t do drugs kids
What is limestone?
Flux/Purifying agent
What is limestones purpose?
Calcium carbonate - removes
impurities during ironmaking
process
How does limestone remove impurities
limestone combines with impurities
• mixture floats to top of metal YOU SLAG
slag can be removed to purify the iron or alloy
What is a blast furnace used for
used for metal and alloy production
– Multi-step process
– Reduction of iron oxide
What are the three basic basic fabrication methods of manufacturing?
Forming, Joining, Casting
What does forming involve
Shaping the metal using
forging tools (wrenches, crankshafts) drawing tools (Rods, wire, tubing)
Rolling (I-beams, rails)
Extrusion (rod, tubing)
What are the casting types?
Sand Casting, Investment Casting, Die Casting, Continuous Casting
What are the joining methods?
Power Processing, Welding
Why are different elements added to steels? Give examples
Different elements are added to steels to give the steel different properties • hardenability • strength • hardness • toughness • wear resistance
What effect does boron have?
Boron: Improves hardenability without loss of
machinability and formability
What effect does calcium have?
Deoxidizes steels, improves toughness, and may improve formability and machinability
What effect does carbon have
Improves hardenability, strength, hardness, and wear resistance;
Reduces ductility, weldability, and toughness
What effect does cerium have
Controls the shape of inclusions and improves toughness in high-strength
low alloy steels; it deoxidizes steels
What effect does Chromium have
Improves toughness, hardenability, wear, corrosion resistance, and
high-temperature strength;
Increases the depth of the hardness penetration
What effect does Cobalt have
Improves resistance to atmospheric corrosion
Adversely affects the hot-working
characteristics and surface quality
What effect does Lead have
Improves machinability; it causes liquid-metal embrittlement
What effect does Magnesium have
has the same effects as cerium
What effect does Manganese have
Improves hardenability, strength, abrasion resistance, and machinability
Deoxidizes the molten steel, reduce shot shortness, and decreases weldability
Here ,
there are way more materials and their affects but
Fuck that, its way too long
learn is yourself you lazy bastard
What is
the most
commonly used metal types
Carbon and alloying steels
Increasing the percentages of alloying elements
in steels..
increases the properties they impart
Properties of Low Carbon Steels?
0.1%% - 0.25%C High formability, high ductility Low Strength Good Weldability Cannot be heat treated
Properties of Medium Carbon Steels?
0.25 -0.55% C
Good combination of strength and ductility
Strengthened by heat treatment
Weldable
Properties of High Carbon Steels?
High hardness, low toughness,
difficult to machine
Low weldability
High strength
Name a high allow steel
Stainless Steel
Properties of stainless steel
corrosion resistance
high strength
ductility
chromium content
What steels are used to make tools?
carbon steels, or alloyed steel
What is Cast Iron?
Iron with 1.7 to 4.5 wt% carbon and 0.5 to 3 wt% silicon
Good castability, low cost
Cast Iron Advantages
- good castability
- antivibration properties
- low stress concentration
Cast Iron disadvantages
- high brittleness
- non machinable (white cast iron, chilled cast iron)
- cold brittleness
What is grey cast iron
Flake graphite in a matrix of pearlite, ferrite or martensite
What is white cast iron
– It is a particular variety of cast iron which
shows white fractures
What is malleable cast iron
Malleable cast iron is obtained from white
cast iron by suitable heat treatment.
It is ductile and may be bent without
breaking or fracturing the section, used for making machine parts
Characteristics of aluminium
Low density, Lightweight, soft, non-magnetic and high corrosion resistance
Two classes of aluminium?
Heat Treatable
Non - Heat Treatable
Properties of heat treatable wrought alloys
- Medium-high mechanical strength
- high ductility
- high corrosion resistance
Properties of non-heat treatable wrought alloys
- Low mechanical strength
- high ductility
- high corrosion resistance
- weldable
Characteristics of Copper
Soft & Ductile
Excellent conductor of heat and electricity
Reasonably good corrosion resistance
4 Groups of Copper
Unalloyed Copper, Brass, Bronze, Other copper alloys
What is brass? Properties?
– copper and zinc alloy
– relatively low melting point
– Hard or soft based on zinc content
– Does not strike sparks
What does brass stand for?
Big retarded and scary sausages
What is bronze? Properties?
– copper and tin alloy
– relatively low melting point
– very ductile
– Low frictional properties
