Materials - 2nd Exam

Incomplete

Non-ferrous alloy

50% up of composition is not iron

Engineering Materials percentage

90% up are iron based

Non-ferrous percentage

10%

Aluminum percentage

5%

Copper percentage

3%

Zn, Mg, Ti, Cr, Ni percentage

2%

Good corrosion resistance

High Electrical and Thermal conductivity

Good Formability and machinability

Specific strength

Appearance

No ductile to brittle transition

What is the main reason to use non-ferrous metals?

Cost

Stiffness (Young's Modulus)

Strength

Quench Hardenable

If the properties of the non-ferrous are true why do we use steel?

Alloying

Cold Work

Precipitation hardening

What are the 3 main techniques to strengthen non-ferrous metals?

Strengthening certain alloys

Soft and weak Al matrix gain strength and hardness by formation of hard particles.

What is Precipitation hardening?

Alloy Al with Cu and/or Mg

Solution Heat Treatment: Heat Solid alloy mix to a region that is a single phase (FCC).

Quench

Provide Time: To gain strength and hardness

Steps of Precipitation Hardening

Natural Aging

Artificial Aging

2 ways of Aging

Ambient Temperature

What is natural aging?

Place in furnace heat up for a shorter period of time.

What is artificial aging?

Aging process the Cu atoms try to get together and form colonies (hard particles) thus gains strength.

What happens to the atomic scale during aging?

All Cu atoms move into AL2Cu and deplete the rest of the matrix from having any copper

Lead to areas of very hard particles in a very soft matrix.

Internal micro sized cracks around particles thus it loses strength and toughness.

What is overaging?

It has high strength levels

What is aged aluminum?

High Production rate and do not need high strength

What is Artificially aged?

Good formability/workability thus low fabrication costs

high strength to weight ratio

Good Corrosion Resistance

Good Electrical and Thermal Conductivity

What are the benefits of Aluminum?

Electrolytic oxidation process thickens protective surface oxide film.

What is anodizing?

Corrosion Resistant

Wear Resistant

Surface can be dyed and painted permanently

What are the benefits of anodizing?

Clean surface of Al with basic solution

Use Electricity to form oxide layer on surface

Boil to seal holes

Steps of Anodizing

oxide

Step 1 of Anodizing: _ Is porous and contains holes

Thickness

Step 1 of Anodizing: it is controlled by electric current

Add Lithium increases stiffness (modulus of elasticity)

Good fatigue crack propagation resistance

Lightweight

Less Deflection

Properties of Aluminum and Lithium Alloys

Corrosion Resistance from Al and Strength and Stiffness from Steel

What is Cladding?

Very conductive

Very corrosion resistant

Very ductile and formable

Very tough at low temp

It is not magnetic

Benefits of Copper and Copper Alloys

Used for wires and electronic connections

Example of benefits of Copper and Copper Alloys

Approximately around 35% Zn and 65% Cu

Properties of Brass?

Bullet Cartridge, Piping, Instruments.

Example of Brass?

35% Zn 65% Cu

Brass that is FC

Brass that is single phase

Properties of Alpha Brass

40% Zn 60% Cu

FCC and HCP

Brass that is 2 phase

Brass not easy to machine

Properties of Beta Brass

Strength and Corrosion Resistant

Good Saltwater Resistant

Brass with Small Sn

Properties of Tin Brass

Brass with improved machinability

Brass with small Pb

Properties of Leaded Brass

copper and tin alloy

Expensive because of Tin

Tin add strength

Good strength toughness and Corrosion Resistance

Low friction coefficient for steel

Properties of Bronze

HCP metal; hard, strong, less ductile

Excellent specific strength strong as steel but lighter

Specific strength used in aerospace and sports cars

Weakest against corrosion - Oxidize early and fast

Ideal to be used as a sacrificial anode for corrosion protection (cathodic protection)

Properties of Magnesium Alloys

HCP metal; hard, strong, less ductile

Sacrificial anode in forms of galvanized steel

Impermeable layer prevents oxygen to reach steel. Thus no ferrous oxide is forming.

Properties of Zinc Alloys

When surface is scratched layer of Zinc acts as a sacrificial anode.

How the layer of Galvanized zinc protects steel?

HCP metal; hard, strong, less ductile

Very Good specific strength

Excellent Corrosion resistance against acids and bases

Non magnetic

Properties of Titanium Alloys

Medical applications, implants, aerospace, bike frames

Examples of Titanium Alloys

Titanium that is Brittle, Super Strong, HCP

Titanium that is hard to fabricate

Titanium with Al, O, N, C

Properties of Alpha Titanium

Titanium with some ductility, and is BCC

Titanium formable with hot work and cold work

Titanium with Mg, V

Properties of Beta Titanium

Titanium that is controlled with higher strength

High strength titanium formable with hotwork

Titanium with Al, O, N, C

Properties of Alpha-Beta Titanium

FCC Metal added to austenitic stainless steel so it is FCC even at room temp.

Ductile (However still very strong)

Non-magnetic

Super excellent corrosion resistance - can be used for food processing

Very creep resistance

Properties of Nickel Alloys

Monel

Ni-Cu

Inconel

Inconel

High MP 2200C - 2800C

Properties of Refractory Metals

Hard to be casted or worked on

Fabricated using powder metallurgy

Properties of Refractory Metals

Blend nano-sized or microsized metal powders

Press it with binder (Green stage)

Fuse via sintering to their final strength.

Steps of powder metallurgy

Polymers, Ceramics, and Composites

Very Important in building the modern world

Polymers

Ceramic

Composites

3 main groups non-metallic materials

Costs

Functionality

They can be very lightweight

Availability and easy to manufacture
Corrosion resistant to acids and bases

What are the main reasons to use non-metallic materials?

Organic Compunds

Living creatures: N, O, S, P, C, H

Inorganic Compounds

Non-living creatures: Metals and Salts

Non polar solvent

Solubility of Organic Compounds

In polar solvents

Solubility of Inorganic Compounds

NaCl polish dissolves by acetone

Solubility example of Organic Compounds

Water, Acids, Bases

Solubility example of Inorganic Compounds

Gases/Liquids/Low Melting Point

Phase of Organic Compounds

Petrol for liquid, Methane for gas, PE is solid

Phase example of Organic Compounds

Generally Solids/ High Melting Point

Phase of Inorganic Compounds

Cl2 for Gas, Mercury for Gas

Phase example of Inorganic Compounds

Covalent or hydrogen bond

Type of bond of Organic Compounds

Ionic or metallic bond

Type of bond of Organic Compounds

It could be

Can organic compounds be polar?

structure is not electrically symmetrical

What is Polar?

A non-polar solvent with symmetrical charge balance.

What is Benzene?

Polymer

Repeated small units in a chain format or "Many units"

Hydrocarbon group

Hydrogen and carbon atoms

Hydrocarbon group

Repeated in identical patterns

Alkane

single bond between carbon atoms

Alkene

double bond between carbon atoms

Alkyne

triple bond between carbon atoms

Aromatic

Circular Structure

Carbon Valency of 4

It can only have 4 bonds around it all of the specified groups

Carbon

It can only form 4 co-valent bonds between other carbon or hydrogen atoms