ME 151 Exam 2
Some properties of aluminum are: - _______ resistance - ______ and ______ conductivity - optical ________
- corossion - thermal and electrical - reflectivity
Magnesium: - ____ strength to weight ratio - strength and density are similar to ______ ______ - _____ (has a higher E)
- high - reinforced plastic - stiffer
Some disadvantages to nonferrous metals and alloys: - ____ cost - lower strength than ______ - ____ modulous of elesticity - ____ weldabilty
- higher - steel - lower - poor
Some characteristics of copper are: - low ____ and high _____ - poor mechanical properties at _____ temps - _____ electrical conductivity - ________ resistant
- strength, ductility - high - high - corrosion
Nonferrous metals and alloys possess: - __________ resistance - are easily _______ - high electrical and thermal _________ - strength at _____ temperatures
-corrosion - fabricated - conductivity - high
Low Carbon Steel = <_____ % Medium Carbon Steel = ____% - _____% High Carbon Steel = _____ % - ______%
1. .2 2. .2-.5 3. .5-2.11
Aluminum Casting Alloys Classification System: First digit indicates? Second and third digit indicates? Last digit indicates?
1. alloy group 2. particular alloy 3. product form
A steel's properties are affected by 3 things:
1. carbon content 2. alloying elements 3. heat treatments
What are the three primary types of stainless steels based on microstructures?
1. ferritic 2. martensitic 3. austenitic
Solidification is done using what two methods?
1. ingot processing 2. continuous steel casting
What are some advantages to continuous steel casting?
1. less wasteful 2. improved surface quality 3. more uniform properties 4. fewer defects
In the Wrought Alloy Classification System: The first number indicates? The second number (___) indicates? The last 2 numbers indicates?
1. major alloy element 2. (0), modification 3. alloy family
In Microalloyed Steels, alloying elements are used here to: (2)
1. reduce grain size 2. cause precipitation hardening
What does secondary refinement do to steels?
1. remove additional carbon 2. add alloying agents 3. remove dissolved gases 4. improve steels cleanliness (remove impurities)
List some of the problems with the Ignot Process.
1. solidification shrinkage/material contracts as it cools 2. trapped gases 3. sometimes wasteful
Three different ways to vacuum degasification.
1. vacuum degassing 2. vacuum are remelting 3. vacuum induction melting
How much chromium does there have to be for a "true" stainless steel?
12%
High alloy steels contain more than ____% alloy additions.
8
Low alloy steels contain less than ___% alloy additions.
8
What are Cast Iron Steels made up of?
A lot of carbon
What is the classification system for magnesium?
ASTM
New steels with high formability (trying to keep material ductile) and strength.
Advanced High-Strength Steels (AHSS)
This type of steel contains alloys in specifiable amounts.
Alloy Steels
in ASTM, the two prefix letters designate the two largest ________ ______.
Alloying metals
Which alloy is the second best to steel?
Aluminum
Made by mixing ceramic particles with molten aluminum and blowing gas into the mixture.
Aluminum forms
Free machining steels have additions that provide ____________.
Built-in Lubricants
Strength is primarily a function of _____ content.
Carbon
Anything above 2.11% carbon is ______ steel.
Cast Iron
What are alloy steels made up of?
Cast Iron Steels with added elements to bring out other properties
If it is cast correctly, iron is classified as _________, and with further processing it is ________.
Cast Iron; Steel
AISI-SAE Classification System classifies steel and steel alloys by ______.
Chemistry
What are some common alloy elements in Alloy steel?
Chromium, Nickel, molybdenum, Vanadium, Tungsten, Cobalt, Boron, and Copper
______ steels and ______ steels are similar to transformation-included plasticity but with higher strength and lower ductility
Complex-Phase and Marstenite
This type of alloy uses AISI designation, require heat treatment to get full strength.
Constructional
What is the most favored way of processing steel?
Continuous Steel Casting
___-____ alloys have: - good high temp strength - good corrosion resistance - used in heat exchangers and cookware
Cooper-nickel
Bronze is made of ______. What is it used for?
Copper-tin; to make bearings and gears
________ can be in the final product of deoxidization.
Defects (pores)
This is a more involved process and produces high quality steel by removing all dissolved gases prior to solidification.
Degassification
Often large amounts of oxygen dissolved in the molten metal
Deoxidation
Materials with high affinity for oxygen; combine with oxygen to form solid oxides that float to the top and can be removed or become dispersed throughout steel.
Deoxidizers
_________ steels- excellent for crash resistance in automotive applications
Dual-Phase
In Free Machining Steels, _____ and _____ properties are lower than unmodified steels.
Ductility;Impact
Copper alloys are the backbone of the ______ industry.
Electrical
What are Copper-Berylium alloys used for?
Electrical contact springs
Remelting steel through slag pool and the slag pool sticks with all impurities and liquid steel continues to drip through
Electroslag Remelting
This type of degasification removes all impurities but is the most expensive.
Electroslag Remelting
These steels machine readily and form small chips when cut (reduces friction on the cutting tool)
Free machining steels
This process decreases the amount of carbon, silicon, manganese, phosphorous, and sulfur in pig iron or steel scrap.
Furnace Oxidation
This type of cast iron is least expensive and most common. (used in automotive engine blocks, heads, and cylinders)
Gray
All plain carbon steels have fairly low _______.
Hardenability
A type of process where contaminants rise to top, forming a slag layer that can be removed.
Ingot Processing
What is the 4th most abundant element in the earth's crust?
Iron
_____ is the lightest of all metallic alloys.
Lithium
What is the lightest alloy of commercially important metals?
Magnesium
______ property makes it easy to separate from other materials.
Magnetic
This type of cast iron has greater ductility than gray cast iron.
Malleable
_____ Steels are used when extremely high strength and toughness is required.
Maraging
Free-Machining Steels have higher ______ cost, and lower _______ cost.
Material,Machining
Result of this type of steel is: increase in strength, even at fairly low carbon %, and without extensive heat treatment.
Microalloyed Steels
This type of alloy steel uses a very small amount of alloying elements.
Microalloyed Steels
For Microalloyed Steels, they are trying to change the ________ and not really the chemistry.
Microstructure
Aluminum is _____ expensive than steel.
More
Maraging Steels have a very high ______ content.
Nickel
What two types if engineering materials have started to be used a lot more?
Nonferrous metals and alloys
Stainless steels form self-healing native ______ _______ on surface.
Oxide Layer
Porosity problems can be avoided if the ________ is removed prior to solidification.
Oxygen
What metal is made from iron ore?
Pig Iron
What is lead used for?
Plumbing components
____ Steels have good electrical and magnetic properties.
Silicon
When is it better to use steel and when is it better to use aluminum?
Steel: cost, fatigue Aluminum: weight, corrosion resistance is needed
What is the only difference in the different Vacuum based degasifications.
The way they turn back into liquid.
What are Plain-Carbon Steels made up of?
There isn't much to them (mostly iron and some carbon)
This is a specialty subcategory of steel alloys particularly well suited for making tools.
Tool Steels
________ steels- excellent energy absorbtion during crash deformation.
Transformation-included plasticity
This type of cast iron has a white surface that appears when the material is fractured.(very hard and brittle)
White
Brass is made of ____. What is it used for?
Zinc; decorative purposes
Which is lighter? Aluminum or steel?
aluminum
What is Aluminum-Bronze made of?
aluminum and copper
oxide coating can be thickened using electricity and is porous, so it can be dyed
anodizing
_____ alloys: melted and poured into mold; low melting temp, high fluidity (low viscosity)
cast
Metal properties are strongly influenced by their ________ and _________.
chemical composition; processing
For High-Strength Low-Alloy Structural Steels, strength comes from _________ composition and no ______ __________ is necessary.
chemical; heat treatment
What type of alloy does Stainless Steel contain?
chromium
In AISI-SAE: First number indicates __________. Second number designates a __________. Last two digits indicate _________.
first: major alloying elements second: subgrouping within the major alloy system last: the carbon percentage
Magnesium is very ______ but not _________ in bulk.
flammable
What is pure zinc used for?
galvanizing
High-Strength Low-Alloy Structural Steels have a ______ cost and _____ strength to weight ratio.
higher
What is plain carbon steel made up of?
iron and carbon
Lead can serve as what two things?
lubricant and chip breaker
Aluminum makes a protective _____ layer which causes difficulty when ______.
oxide; welding
What is a silicon-bronze made of?
silicon and copper
________ decreases subsequent cooling and solidification; ________ and other gases are rejected
solubility; oxygen
Name 4 of the properties of steel.
strength; rigidity; durability; tensile strength; stress strength; high elastic modulus
Typically, tool steels have good _____, ____ _______, and ______ when heat treated.
strength; wear resistance; toughness
Why is pure aluminum rarely cast?
they can shrink and crack
The selection process of an alloy steel: consider both _____ and ________.
use and fabrication
Name some bad properties of aluminum.
wear and fatigue resistance are lower, lower strength at high temps
_____ alloys: solid- meant to be formed; low strength and high ductility
wrought