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