IENG 2020 Final Exam review Spring 2025

Sources of Manufacturing Hazards

• Material handling
• Hand-held tools
• Machining
• Electrical
• Noise
• Vibration
• Chemical
• Fire
• Bloodborne pathogens
• Slips, trips, falls
• Stress
• And many more

Effects of Hazardous Substances

• Irritant: Noncorrosive that causes dermatitis or lung inflammation.
• Corrosive: Attacks living tissue by burning.
• Harmful: May pose health risks if swallowed, inhaled, or upon skin penetration.
• Toxic: Impedes or prevents the function of one or more organs.
• Carcinogen: May cause cancer.
• Acute: Health problems occur rapidly soon after exposure.
• Chronic: Health problems develop over time.

Personal Protective Equipment (PPE)

• If PPE is needed, employees must be trained to use and maintain it.
• In some cases, the employer pays for the PPE.
• If an employee is assigned to a new area, they should be trained in proper PPE use for the new assignment.

Chemical Hazards

• Coolants
• Lubricants
• Abrasive slurry
• Dielectric liquids
• Gases
• Proper labeling is a must!

Importance of Manufacturing Technology

• Raw materials are transformed into finished goods.
• Mass production vs. custom.
• Value Adding Activity
  • Add value while reducing waste
• Tools
  • Machines, CAD software, SPC
• Advanced Manufacturing
  • Rapid transfer of science and technology into mfg. products and processes
• Quality Assurance, Total Quality Control, Quality Control

Manufacturing Flow

• Raw Materials → Supplier → Manufacturing → Distribution → Consumer/Customer

Selection of Materials and MFG. Processes

• "Manufacturability" is key.
• Consider:
  • Replacing with less expensive materials
  • Avoiding materials that unnecessarily exceed minimum requirements
  • Appropriateness for selected process
  • Availability in needed size and quantity
  • Supply reliability
  • Price stability
  • Strategic importance
  • Qualified vendor

Selection of the Process

• Properties of material
• Shape and size of the product
• Accuracy of shape and size
• Surface quality
• Functional requirements of the product
• Batch size
• Level of automation
• Manufacturability
• Alternative processes
• Cost to manufacture

Classification of Mfg. Processes

• Smelting and casting
  • Expendable mold
  • Permanent mold
• Plastic forming
  • Mechanical force beyond yield stress limit
• Powder metallurgy
  • Near net shape part
• Machining Processes
  • Milling, Turning, non-traditional
• Joining processes
  • Welding, gluing
• Surface Treatment
  • Honing, polish, grinding
• Heat Treatment
  • Change properties/crystalline structure
• Assembly
  • Hard: using machines, feeders, mass production
  • Soft: Robotics, PLC control, or computer
• Modern Mfg. Processes
  • Nanotech., sustainable, green
• Complimentary processes
  • Inspection, material handling, storage, packaging

Stress Strain Diagram for Plastic Forming

• Illustrates the relationship between stress and strain in a material subjected to plastic forming.
• Key regions and points:
  • Linear elastic range: Stress is proportional to strain; material returns to original shape after unloading.
  • Elastic limit: Point beyond which the material will experience permanent deformation.
  • Yield stress: Stress at which significant plastic deformation begins.
  • Plastic range: Material undergoes permanent deformation.
  • Failure: Point at which the material fractures.
• Plastic deformation: Permanent change in shape after stress is removed.

Planning for Manufacturing

• Interdependent relationships between:
  • Design
  • Cost reduction
  • Design for manufacturability
• Goal: High quality while minimizing cost.
• Key considerations:
  • Selection of material
  • Selection of process
  • Selection of equipment

Accuracy of the Manufacturing Process

• Tolerances:
  • Close tolerances should only be used when absolutely necessary.
  • Require extra resources, trained personnel, and more expensive machines.
  • Increase cost and time to create.
  • Difficult to measure and hold to specification.
  • If a close tolerance is not required, give as much tolerance as possible.

Economical and Environmental Considerations

• Hazardous Waste
• Labor laws
• OSHA (Occupational Safety and Health Admin.)
• EPA (Environmental Protection Agency)
• DFE (Design for Environment)
• Product life cycles (cradle to grave and back again)
• Use non-toxic materials
• Use non-toxic processes
• Minimize energy usages
• Minimize scrap

Physical Properties

• Density
• Thermal
• Electrical
• Chemical
• Optical
• Corrosion resistance
• etc.

Mechanical Properties

• Strength: The ability of a material to resist stress.
  • Stress-strain diagram
  • Tensile tests
  • Elastic limit
  • Young’s modulus
  • Elastic and plastic deformation

Mechanical Properties - Ductility

• Ductility: Area under the stress-strain curve within the plastic deformation range.

Mechanical Properties - Brittleness

• Materials that have a sudden failure without any change in length or diameter before failure are brittle.

Mechanical Properties - Toughness

• How much stress/energy is required to break the material.
• Impact strength
• Charpy Impact or Izod test

Mechanical Properties - Hardness

• How well does the material resist penetration; non-destructive and widely used to indicate other mechanical properties.

Relative Hardness of Common Metals

• Hardness Scale (from hardest to softest):
  • Diamond
  • Advanced Ceramic
  • Carbide
  • Titanium
  • High Carbon Steel
  • Stainless Steel
  • Aluminum
  • Tin
• Advanced Ceramic is second only to diamond in hardness.

Mechanical Properties - Hardness Tests

• Types of hardness tests:
  • Brinell (HB)
  • Rockwell (HR)
  • Vickers (HV)
  • Knoop (Hk)
  • Mohs (HM)
  • Scleroscope
  • Durometer
  • File

Brinell Hardness (HB)

• Three levels of weight (500, 1500, 3000kg)
• 10 mm steel ball
• Time is 5 to 10 seconds for test
• Dent in material is measured and a chart is used to determine the test result

Rockwell Hardness (HR)

• Rockwell Hardness Test setup includes:
  • Penetrator
  • Specimen
  • Anvil
  • Elevating screw
  • Handwheel
  • Zero adjuster
  • Trip lever
  • Weights
  • Weight pan
• Different scales and indenters are used for various materials. Examples include:
  • A (HRA): Cone indenter, 60 kg load, used for carbides and ceramics.
  • B (HRB): 1.6 mm ball indenter, 100 kg load, used for nonferrous metals.
  • C (HRC): Cone indenter, 150 kg load, used for ferrous metals and tool steels.

Vickers and Knoop Hardness Tests

• Vickers Hardness Test:
  • Uses a pyramid-shaped diamond of 136° angle.
  • Load F ranges from 1 to 120 kgf.
  • Diagonal of indention (D) is measured.
• Knoop Hardness Test:
  • Uses a Knoop Diamond Pyramid Indenter.
  • Micro-Vickers.
  • Load F ranges from 1-1000 gf.
  • Diagonal of indention (D) is measured.

Mohs Hardness Scale

• A qualitative scale characterizing the scratch resistance of minerals.
• Ranges from 1 (Talc) to 10 (Diamond).
• Examples:
  • Diamond (10)
  • Corundum (9)
  • Topaz (8)
  • Quartz (7)
  • Orthoclase (6)
  • Apatite (5)
  • Fluorite (4)
  • Calcite (3)
  • Gypsum (2)
  • Talc (1)
• Common Objects:
  • Masonry Drill Bit (8.5)
  • Steel Nail (6.5)
  • Knife/Glass Plate (5.5)
  • Copper Penny (3.5)
  • Fingernail (2.5)

Scleroscope Hardness Test

• Uses the height of rebound of a diamond-tipped hammer from the test specimen surface to determine hardness.

Durometer Hardness Test

• Measures the hardness of soft materials, such as rubbers and polymers.
• Involves pressing an indenter into the material under a specific load and measuring the depth of penetration.

Mechanical Properties - Fatigue

• Damage due to repeated tension and compression stress or cycles.
• Defects are often where fatigue failure begins.
• Most mechanical property failures are due to fatigue.
• Design can also create areas where fatigue cracks start from; i.e., keyways, surface finish, gouges from machining or other work.

Mechanical Properties - Creep

• Time-dependent deformation of a material under an applied load below its yield strength, often at elevated temperatures.
• Materials in service are often exposed to elevated temperatures or static loads for a long duration of time.
• Creep is a deformation mechanism that may or may not constitute a failure mode.

Manufacturing or Fabrication Properties

• Can you cast it in a mold?
• Is it ductile, formable, etc.?
• Can you machine, grind it easily?
• Can it be welded?
• Can you heat treat it?

The 0.001-Inch Micrometer

• Components:
  • Anvil
  • Spindle
  • Sleeve (Barrel)
  • Thimble
  • Barrel Scale
  • Thimble Scale
  • Reading Line
• The part to be measured is placed between the anvil and the spindle.
• The barrel of a micrometer consists of a scale, which is one inch long.
  • The one-inch length is divided into ten divisions each equal to 0.100 inch.
  • The 0.100-inch divisions are further divided into four divisions each equal to 0.025 inch.
• The thimble has a scale that is divided into twenty-five parts.
  • One revolution of the thimble moves 0.025 inch on the barrel scale.
  • Therefore, a movement of one graduation on the thimble equals 1/25 of 0.025 inch or 0.001 inch along the barrel.

Micrometer Features

• Functional Features:
  • Ratchet Stop
  • Thimble
  • Barrel
  • Clamp Ring
• Metrological Features:
  • Thimble Scale
  • Barrel Scale
  • Spindle
  • Head
  • Screw Length
  • Observed Value
  • Anvil
  • Reference Point
  • Frame
  • Distance Under Observation

Reading a Micrometer

• Inches
  • Each large division on the barrel scale is 0.100"
  • Each small division is 0.025"
  • Each division on the thimble scale is 0.001"
• Metric
  • Each major division is 1 mm, minor divisions are 1/2 mm or 1 revolution.

Reading Metric Micrometers

• Read whole millimeters
• Read half millimeters
• Read hundredths of millimeters

Dial Indicator

• Measures small distances or variations using a dial.
• Key components mentioned: Plunger, Main Scale
• Main Scale Divisions: One division equals 0.001 inches.
• One revolution of needle completes one rotation of the main scale

Reading the dial indicator

• Add measurements from each step to get the final measurement
• Example calculation:
  4.00 mm + 0.20 mm + 0.06 mm = 4.26 mm

Types of Atomic Arrangements

• Crystalline: Atoms are arranged in a geometric array; seen in solid metals, alloys, and most minerals.
• Amorphous: Atoms have some order, but lack the long-range arrangement of a crystalline solid; seen in glass, rubber, plastic, asphalt

Types of Bonds Between Atoms

• Ionic Bonds: Transfer electrons between atoms.
• Covalent Bonds: Share electrons.
• Metallic Bonds: Created by free electrons or electron cloud.
• Molecular Bond: From electrical attraction.

Lattice Structure of Metals (Metallic Bonds)

• The metallic structure found in metals and alloys gives these materials strength, electrical and thermal conductivity, and other desirable properties.

Typical Crystalline Lattice Structures

• Body-Centered Cubic (BCC)
  • Examples: Chromium, tungsten, iron
• Face-Centered Cubic (FCC)
  • Examples: Aluminum, copper, silver
• Close-Packed Hexagonal (CPH)
  • Examples: Zinc, magnesium, cadmium

Space Lattice

• Body Centered Cubic (BCC)
  • Cr, W, Ti, Ta, V, certain types of Fe
• Face Centered Cubic (FCC)
  • Al, Cu, Ni, Au, Ag, types of iron Fe
• Hexagonal close-packed (hcp)
  • Less ductile, found in Zn, Mg, Zr, Ti, Cd etc.

Metallic Crystal Structures - BCC

• (a) Hard-sphere unit cell
• (b) Reduce-sphere unit cell
• (c) Lattice (space lattice)
• a = \frac{4R}{\sqrt{3}}

Metallic Crystal Structures - FCC

• (a) Hard-sphere unit cell
• (b) Reduce-sphere unit cell
• (c) Lattice (space lattice)
• a = 2R\sqrt{2}

Metallic Crystal Structures - HCP

• (a) Hard-sphere unit cell
• (b) Reduce-sphere unit cell
• (c) Lattice (space lattice)
• a = 2R

States of Matter

• Solid
• Liquid
• Gas
• Plasma

Allotropic (Polymorphic) Crystals

• Some metals can exist in the solid state in two or more lattice forms depending on temperature and sometimes on pressure.
• Iron is one of these; this property makes heat treatment of iron and its alloys possible.

Phase Diagram of Iron

• As metals are heated, they change from a solid to a liquid.
• Internally, the atomic bonds lessen allowing atoms to move.
• The more carbon you add to iron affects the arrangement of the atoms.

Classification of Engineering Materials

• Metallic Materials and Alloys
  • Ferrous (steel, cast Iron)
  • Non-Ferrous (aluminum, copper, etc.)
• Non-Metallic
  • Natural
  • Synthetic

New Materials

• Foam Metal
• Nano
  • Amorphous
  • Crystalline
• Shape Memory Alloy

Mechanical Properties of Materials

• Mechanical properties are very important when choosing a material.
• Design Considerations:
  • Is the design static (stationary) or dynamic (moving)?
  • How well will the material handle a load under a static or dynamic condition?
• Types of Mechanical Properties:
  • Strength
  • Ductility and Brittleness
  • Toughness
  • Hardness
  • Fatigue
  • Creep

Ferrous Metals and Alloys

• Contain Iron (Fe).
• Steel:
  • Steel designation: 10XX plain carbon steel. XX is the carbon content.
  • Steel carbon content: Up to 2%.
• Cast Iron:
  • From 2% to 4.3% carbon.
  • Types: White cast iron, Malleable cast iron (annealed), Gray cast iron.

General Categories of Steel Alloys

• Carbon Steels - Surface Hardness and Strength
• Nickel Steels - Toughness
• Chrome-Nickel Steels - Toughness and Depth Hardness
• Molybdenum Steels - Eliminates Brittleness and increases Depth Hardness
• Chrome-Molybdenum Steels - High Strength and Toughness
• Chromium Steels - Corrosion Resistance and Hardness
• Chrome-Vanadium - Depth Hardness and Toughness at Sub-zero Temperature
• Tungsten Steels - Hardness at High Temperatures
• Chrome-Nickel-Molybdenum Steels - Toughness and Strength (General Purpose Steel)
• Silicone-Manganese Steels - Depth Hardness and Toughness Under Impact

Plain Carbon Steel

• Iron is the base with small amounts of carbon and trace amounts of Mn, Si, and Cu.

Plain Carbon Steel Applications

• Lower Carbon Content (0.08% to 2.0%):
  • More ductile material.
  • Applications: Nails, wire, pipe, rivets

Medium Carbon Steel

• Carbon content 0.3% to 0.8%.
• Same alloying elements as plain carbon steel.
• Quench can increase hardness: Cooling process using water, brine, or oil.
• Applications:
  *Gears
  *Shafts
  *Axles
  *Punches
  *Dies
  Etc.
• Give up a little ductility for more strength.

Heat Treat and Quench

• Heat Treatment (HT):
  • Temperature is applied to alter physical (sometimes chemical) properties of a material.
  • The desired property of a material determines the temperature for HT.
  • Heat and/or cooling (to very low temperatures) are used.
• Quench:
  • Rapid cooling (within seconds) using different types of media.
  • Used to discourage undesirable phase transformations that may happen if cooling is not fast enough.
  • Used to create small grain size in the crystalline structure.

Heat Treat and Quench

• Annealing and Normalizing
  • Used as a slow cooling type heat treat process instead of a fast quench process.
  • The slower the cool down, the larger the grains and material are allowed to reach equilibrium.
• Quenching
  • The faster the cool down the harder the material; water is the fastest quench.

Steel Alloys

• High Strength Low Alloy (HSLA)
• Quenched and Tempered Low Carbon
• AISI – SAE Alloy Steel
• Alloy Tool and Die Steels
• Stainless Steel
  • Ferritic stainless steel
  • Martensitic stainless
  • Etc.

SAE/AISI Steel Designations

• Series:
  • 1XXX: Carbon steels
  • 2XXX: Nickel steels
  • 3XXX: Nickel-chromium steels
  • 4XXX: Molybdenum steels
  • 5XXX: Chromium steels
  • 6XXX: Chromium-vanadium steels
  • 7XXX: Tungsten-chromium steels
  • 9XXX: Silicon-manganese steels
• Percentage of major element to nearest whole number (except series 1).
• Carbon content = last two numbers of steel designation

How are Alloys Created?

• Alloy: A substance having metallic properties, consisting of two or more elements, or of metallic and nonmetallic elements, which are miscible with each other when molten, and have not separated into distinct layers when solid.
• Ferrous Alloys
  • Iron (Fe) is the base (at least 50%)
  • Other elements such as chromium, titanium, copper are added to create the alloy and to enhance the ferrous metal’s properties.
• Non-Ferrous Alloys
  • Any nonferrous element can be the base (at least 50%)
  • Additional elements are added to enhance base metal’s properties.

Recipe for Stainless Steel Alloy

• Varying compositions exist to achieve different properties, including variations in Cr, Ni, Mo, and other trace elements.

High-Strength Low-Alloy Structural Steel (HSLA)

• Not enough carbon to be heated and then quenched to increase strength.
• Relies on chemical composition for mechanical properties.
• Used in large structural applications where heat treatment /quench operation is not an option.

Low Carbon Construction Alloy Steel

• Slightly higher carbon content than HLSA.
• Alloyed with V, Mo, and Ti.
• Used for pressurized tanks, mining equipment, etc.

American Iron and Steel Institute (AISI) – Society of Automotive Engineers (SAE)

• These steels are always heat treated.
• Lower carbon – carburized treatment.
• Higher carbon – quenched and tempered treatment.
• Alloyed with Mn, Mo, Cr, Ni.
• Examples: Automobile bodies (ductile) to ball bearings (hard).

AISI/SAE Common Uses

• Most common, also have Unified Numbering System (UNS) and ASTM

Alloy Tool and Die Steels

• These steels are high carbon alloys.
• High carbon means tough and wear-resistant.
• However, too much carbon will cause the steel to become brittle.

Stainless Steels

• High chromium (11% to 12%) content makes this steel alloy corrosion resistant.
  • Austenitic: Along with Cr, you have Ni and Mn; non-magnetic ferrous-based steel used for Stainless steel kitchenware.
  • Ferritic: Higher Cr but without Ni; weldable, used for auto trim and kitchenware.
  • Martensitic: Can be heat treated to increase hardness; therefore, high strength, fatigue resistant, used for turbine blades.
  • Precipitation hardened: The addition of Cu, Al, and Ti or Mo. Precipitation means metallic additions are introduced during heat treatment.
  • Duplex: High Cr content, used in heat exchange units.

Cast Irons

• Manufacture-ability
• Cheap
• Easy to cast
• Easy to machine
• Good properties
• Dampening ability
• Good wear resistance

Classification of Cast Irons

• White cast iron
• Malleable cast iron
• Gray cast iron
• Spheroidal
• Alloy

White Cast Iron

• Rapid cooling when being cast; this type of cast iron maintains a high level of iron carbide (cementite).
• Cementite is hard and brittle and is known as Fe_3C
• Used in crushing, grinding, milling, and handling of abrasive materials such as minerals and ores.

Malleable Cast Iron

• Made by heating white cast iron and then using a slow quench or cooling process.
• This allows grains within the material time to almost reach equilibrium.
• It is used for small castings and castings with thin walls.
• Graphite flakes are small stress risers in your casting.

Gray Cast Iron

• More Graphite
• Increase Carbon
• Increase Si and Ni
• Decrease cooling rate
• Cooling of Gray cast iron
  • Fast Cooling = Graphite flakes in Pearlite
  • Medium = flakes in Pearlite and Ferrite
    • Produces good combo or strength and ductility
  • Slow = flakes in Ferrite

Ductile, Nodular, or Spheroidized Cast Iron

• Mg is added during the casting process.
• Graphite changes from flake shape to ball shape.
• Has higher ductility due to graphite shape.

Alloy Cast Irons

• As before – the main purpose of alloying is to enhance the mechanical properties of the base material.
• Characteristics of alloy cast irons:
  • Non-magnetic
  • High thermal and electrical properties
  • Resistant to corrosion
• Uses
  • Pump castings
  • Chain wheel
  • Bull gear
  • Flywheels
  • Impellers
  • Friction brake drums
  • Etc.

Non-Ferrous Metals and Alloys

• Disadvantages
  • More costly than ferrous metals and alloys
  • Strength is not as good as ferrous metals
  • Lower melting points than ferrous metals
  • Weldability not as good as ferrous metals
• Advantages
  • High ductility
  • Lightweight
  • More manufacturable than ferrous metals

Aluminum Alloys

• Many uses for aluminum alloys – better to show entire markets for the material
  • Aerospace
  • Aluminum cans
  • Automotive
  • Construction
  • Electrical
  • Electronics
  • Foil and packaging
  • Other markets
• Very expensive to extract from Bauxite ore.
  • Uses electrical energy to release aluminum from the ore.
  • Uses around 95% less electrical energy to recycle because of its low melting point. (1220 degrees F or 900-940 degrees Celsius

International Alloy Designations for Wrought Aluminum

• Based on the major alloying element:
  • 1XXX: 99.00% min. Aluminum
  • 2XXX: Copper
  • 3XXX: Manganese
  • 4XXX: Silicon
  • 5XXX: Magnesium
  • 6XXX: Magnesium and Silicon
  • 7XXX: Zinc
  • 8XXX: Other Elements

Is Aluminum Heat Treatable?

• If aluminum has a low melting point, can it be heat treated?
• Depends on the alloy.

Magnesium and Magnesium Alloys

• Lightest of metals used for engineering design.
• Mg alloys are weak, so they need to be alloyed with Al and or Zn.
• Easy to machine.
• Good vibration dampening.
• Highly combustible when in small chip or powder form!
• Used for ladders, portable power tools (lightweight), bicycles, sporting goods.

Zinc and Zinc Alloys

• The main characteristic of zinc is its corrosion resistance.
• Often used as a coating for other metals “galvanized”.
• Used as a base metal in die casting.
• Almost always used as an alloy with Al and Cu added to give it strength.

Lead, Tin, and White Metals

• Lead (Pb)
  • Resistant to acid
  • Radiation shielding
  • Toxic
• Tin (Sn)
  • Protective coating
  • Used inside food cans
• Alloys of lead and tin
  • Low melting temp.
  • Bearing alloy and fusible alloy
• Bearings
  • Soft and easy to cast, used when surfaces contact each other
• Solder
  • Usually a tin alloy more so than lead due to toxicity~

Copper and Copper Alloys

• Great thermal and electrical properties
• Attractive appearance
• Corrosion resistant
• Bacterial resistant

Copper Alloys

• Copper + Zinc = Brass
  • Ductile
  • Cartridge brass
  • Easy to form/deep draw
• Copper + Tin = Bronze
  • Tough
  • Used for gears, pump parts
• Bronze + Aluminum
  • High strength from Al and excellent corrosion resistance from bronze
• Bronze + Silicon
  • High strength, machinable, weldable
• Beryllium + Bronze
  • Expensive because of Be
  • Toxic because of Be
  • Strength of steel
  • Nonsparking, nonmagnetic
• Copper + Nickel (cupronickels)
  • High thermal properties; good for heat exchangers
  • Nickle silver – no silver, only looks like it
• Constantan: High electrical resistance and is used in thermocouples

Nickel and Nickel Alloys

• Ni = adds strength, toughness, corrosion resistance to other metals
• Nichrome contains Cr and/or Cr+Fe
  • High resistance to corrosion at high heat, therefore, they are used in electrical resistance heater elements
• Nickel plate is used for appearance

Nickel Alloys

• Inconel
  • High temps do not affect corrosion resistance (900 deg. Celsius = 1652 deg. Fahrenheit)
  • Used in food processing
• Monel
  • Used in the food processing
    industry and steam turbine blades
• Invar
  • Coefficient of expansion is near 0 between 32 F and 212 F
• Kovar
  • Heat-resistant
• Permalloy
  • Used in transformers with high frequency

Titanium

• Titanium adds corrosion resistance and is relatively lightweight.
• Alloys are used as substitutes for Stainless steels when corrosion and strength are concerned.
  • Three different structures
  • Hexagonal closed pack (HCP) space lattice
  • BCC space lattice
  • Hybrid of both HCP and BCC

Suuuper Alloys!!!

• Properties come from Ti, Ni, Co.
• High tensile strength and high heat.
• Good corrosion resistance.
• High toughness and ductility.
• Good at cold temperatures.

Refractory Metals

• Refractory = used in a high temperature application such as a jet engine exhaust.
• Examples:
  • Molybdenum melt pt = 4748 degrees Fahrenheit
  • Niobium melt pt = 4478 degrees Fahrenheit
  • Tantalum melt pt = 5486 degrees Fahrenheit
  • Tungsten melt pt = 6170 degrees Fahrenheit
  • Rhenium melt pt = 5756 degrees Fahrenheit
• Tungsten = used as a lightbulb filament
• Beryllium = very costly, but it is lightweight, used in atomic energy applications
• Zirconium = good strength, ductility, and corrosion resistance at high temperature, so it is used in nuclear reactors.

Noble Metals

• Resist oxidation and acids.
  • Silver: Better than copper for conducting thermal and electrical energy.
  • Gold: Used for electrical contacts that cannot be allowed to corrode.
  • Platinum: Used in the catalytic converters.
  • Others: Ruthenium, Rhodium, Palladium, Osmium, Iridium

Platinum in Catalytic Converters

• Platinum (Pt), Rhodium (Rh) Palladium (Pd) are used in catalytic converters

New Materials

• Nanomaterials
• Amorphous materials
• Metal Foams
• Shape Memory Alloy

Nano Material Relative Sizes

• Sizes vary from 10 nm to 10^6 nm

Nanomaterials

• Elements that are reduced to nano size exhibit unusual properties.
• Gold’s inert property becomes reactive in the nanoparticle range and may appear deep red or black when it is nano-sized.
• Stable materials become unstable.
• Copper nanomaterial is not ductile like bulk copper wire.
• Nanoparticles have been used to aid in drug delivery and biosensors application for tumor diagnosis and therapy.
• High surface area to volume lends nanoparticles to applications that require high diffusion of other materials, i.e., medicine.
• For paint, it is used to increase UV resistance.

Amorphous Alloys

• Disordered space lattice
• Non-crystalline
• No grain boundaries
• Grain structure is similar to glass, so they are nicknamed “glassy metals” or “metallic glasses.”

Uses for Amorphous Materials

• Tennis rackets
• Baseball bats
• Wristwatches
• Scratch resistant cell phone casings
• Orthopedic implants
• Scalpels
• Amorphous materials have high wear and corrosion resistance.
• Low coefficient of friction
• High-temperature performance

Metal Foams

• Low density and weight.
• Pores are either open or closed.
• Very low weight but strong.
• Sound dampening.
• Filtration.
• Orthopedic implants.
  • Allows for bone to grow into mesh.

Shape Memory Alloys

• These alloys are able to be bent and then return to their original shape and size (working within the elastic limit).

Steel Making

• From the blast furnace, pig iron, scrap steel, or a combination of both is used in the production of steel.
• The goal in refining steel is to remove impurities.
• Bessemer converter, oxygen converter, electric