ADVANCED MATERIALS

Prof. Stepan MudryUNIVERSITY OF LVIV

Ivan Franko National University of Lviv.

Marian SmoluchowskiLviv 1898-1913

• Smoluchowski's scientific output included fundamental work on the kinetic theory of matter. In 1904 he was the first who noted the existence of density fluctuations in the gas phase and in 1908 he became the first physicist to ascribe the phenomenon of critical opalescence to large density fluctuations. His investigations also concerned the blue colour of the sky as a consequence of light dispersion on fluctuations in the atmosphere, as well as explanation of Brownian motion of particles. At that time Smoluchowski proposed formulae which presently carry his name.

Content-Classification of materials

-Amorphous metallic alloys

-Nanocrystalline materials

-Composite materials

-Magnetocaloric materials

-Semi-solid metals

-Shape memory alloys

-Ferrofluids

-Energetic materials

Why Materials ???

Ashby,: Material Selection in Mechanical Design

Competition of materials

Traditional materials - advanced materials

-weight reduction strategy;-corrosion resistance increase;-environment protection;-cost reduction;-new working capabilities- upgrade functions

MATERIALS SCIENCE

Physics-------Chemistry-------Mathematics

Crystalline structure, chemical bonding, physical properties, thermodynamics, physical and chemical kinetics, surface phenomena, mathematical models, computer simulation methods, fractal geometry, statistical physics, electronic structure

Engineering Materials

Materials

Nanomaterials, shape-memory alloys, superconductors, …

Ferrous metals: carbon-, alloy-, stainless-, tool-and-die steels

Non-ferrous metals: aluminum, magnesium, copper, nickel,titanium, superalloys, refractory metals,beryllium, zirconium, low-melting alloys,gold, silver, platinum, …

Plastics: thermoplastics (acrylic, nylon, polyethylene, ABS,…)thermosets (epoxies, Polymides, Phenolics, …)elastomers (rubbers, silicones, polyurethanes, …)

Ceramics, Glasses, Graphite, Diamond, Cubic Boron Nitride

Composites: reinforced plastics, metal-, ceramic matrix composites

Properties of materials

Mechanical properties of materialsStrength, Toughness, Hardness, Ductility,Elasticity, Fatigue and Creep

Chemical propertiesOxidation, Corrosion, Flammability, Toxicity, …

Physical propertiesDensity, Specific heat, Melting and boiling point,Thermal expansion and conductivity,Electrical and magnetic properties

Material Specification

• Chemical composition

• Mechanical properties – Strength, hardness (under various conditions: temperature, humidity, pressure)

• Physical properties – density, optical, electrical, magnetic

• Environmental – green, recycling

Metals

• Ferrous Metals– Cast irons

– Steels

• Super alloys– Iron-based

– Nickel-based

– Cobalt-based

• Non-ferrous metals– Aluminum and its alloys

– Copper and its alloys

– Magnesium and its alloys

– Nickel and its alloys

– Titanium and its alloys

– Zinc and its alloys

– Lead & Tin

– Refractory metals

– Precious metals

General Properties and Applications of Ferrous Alloys

• Ferrous alloys are useful metals in terms of mechanical, physical and chemical properties.

• Alloys contain iron as their base metal.

• Carbon steels are least expensive of all metals while stainless steels is costly.

Carbon and alloy steelsCarbon steels• Classified as low, medium and high:

1. Low-carbon steel or mild steel, < 0.3%C, bolts, nuts and sheet plates.

2. Medium-carbon steel, 0.3% ~ 0.6%C, machinery, automotive and agricultural equipment.

3. High-carbon steel, > 0.60% C, springs, cutlery, cable.

Carbonand alloy steels

Alloy steels• Steels containing significant amounts of

alloying elements.

• Structural-grade alloy steels used for construction industries due to high strength.

• Other alloy steels are used for its strength, hardness, resistance to creep and fatigue, and toughness.

• It may heat treated to obtain the desired properties.

Carbon and alloy steels

High-strength low-alloy steels• Improved strength-to-weight ratio.

• Used in automobile bodies to reduce weight and in agricultural equipment.

• Some examples are:

1. Dual-phase steels2. Micro alloyed steels3. Nano-alloyed steels

Stainless steels• Characterized by their corrosion resistance,

high strength and ductility, and high chromium content.

• Stainless as a film of chromium oxide protects the metal from corrosion.

Stainless steels

• Five types of stainless steels:

1. Austenitic steels2. Ferritic steels3. Martensitic steels4. Precipitation-hardening (PH) steels5. Duplex-structure steels

Typical Selection of Carbon and Alloy Steels for Various Applications

T A B L E 5 .1P ro d u ct S teel P ro d u ct S teelA ircraft fo rg ings,

tub ing, fittingsA u tom ob ile bod iesA xlesB all bearings and racesB o ltsC am shaftsC hains (transm ission )C o il sp ringsC onnecting rodsC rankshafts (fo rged )

4140 , 8740

10101040 , 4140521001035 , 4042 , 48151020 , 10403135 , 314040631040 , 3141 , 43401045 , 1145 , 3135 , 3140

D ifferen tia l gearsG ears (car and truck)Land ing gearLock w ashersN u tsR ailroad rails and w heelsS prings (co il)S p rings ( leaf)Tub ingW ireW ire (m usic)

40234027 , 40324140 , 4340 , 87401060313010801095 , 4063 , 61501085 , 4063 , 9260 , 615010401045 , 10551085

Mechanical Properties of Selected Carbon and Alloy Steels in Various Conditions

TABLE 5.2 Typical Mechanical Properties of Selected Carbon and Alloy Steels in the Hot-Rolled,Normalized, and Annealed ConditionAISI Condition Ultimate

tensilestrength(MPa)

YieldStrength(MPa)

Elongation in50 mm (%)

Reduction ofarea (%)

Hardness(HB)

1020

1080

3140

4340

8620

As-rolledNormalizedAnnealedAs-rolled

NormalizedAnnealed

NormalizedAnnealed

NormalizedAnnealed

NormalizedAnnealed

44844139310109656158916891279744632536

346330294586524375599422861472385357

363536121124192412222631

596766172045575036495962

143131111293293174262197363217183149

AISI Designation for High-Strength Sheet Steel

TABLE 5.3Yield Strength Chemical

CompositionDeoxidation

Practice

psi x 103 MPa

35404550607080100120140

240275310350415485550690830970

S = structural alloy

X = low alloy

W = weathering

D = dual phase

F = killed plus sulfide inclusion control

K = killed

O = nonkilled

Room-Temperature Mechanical Properties and Applications of Annealed Stainless Steels

TABLE 5.4 Room-Temperature Mechanical Properties and Typical Applications of Selected AnnealedStainless Steels

AISI(UNS)

Ultimatetensile

strength(MPa)

Yieldstrength(MPa)

Elongationin 50 mm

(%) Characteristics and typical applications303(S30300)

550–620 240–260 53–50 Screw machine products, shafts, valves, bolts,bushings, and nuts; aircraft fittings; bolts; nuts;rivets; screws; studs.

304(S30400)

565–620 240–290 60–55 Chemical and food processing equipment,brewing equipment, cryogenic vessels, gutters,downspouts, and flashings.

316(S31600)

550–590 210–290 60–55 High corrosion resistance and high creep strength.Chemical and pulp handling equipment,photographic equipment, brandy vats, fertilizerparts, ketchup cooking kettles, and yeast tubs.

410(S41000)

480–520 240–310 35–25 Machine parts, pump shafts, bolts, bushings, coalchutes, cutlery, tackle, hardware, jet engine parts,mining machinery, rifle barrels, screws, andvalves.

416(S41600)

480–520 275 30–20 Aircraft fittings, bolts, nuts, fire extinguisherinserts, rivets, and screws.

Tool and die steels

• Designed for high strength, impact toughness, and wear resistance at a range of temperatures.

Basic Types of Tool and Die Steels

TABLE 5.5Type AISIHigh speed

Hot work

Cold work

Shock resisting

Mold steels

Special purpose

Water hardening

M (molybdenum base)T (tungsten base)H1 to H19 (chromium base)H20 to H39 (tungsten base)H40 to H59 (molybdenum base)D (high carbon, high chromium)A (medium alloy, air hardening)O (oil hardening)SP1 to P19 (low carbon)P20 to P39 (others)L (low alloy)F (carbon-tungsten)W

Processing and Service Characteristics of Common Tool and Die Steels

TABLE 5.6 Processing and Service Characteristics of Common Tool and Die Steels

AISIdesignation

Resistance todecarburization

Resistance tocracking

Approximatehardness(HRC) Machinability Toughness

Resistance tosoftening

Resistance towear

M2 Medium Medium 60–65 Medium Low Very high Very highT1 High High 60–65 Medium Low Very high Very highT5 Low Medium 60–65 Medium Low Highest Very highH11, 12, 13 Medium Highest 38–55 Medium to high Very high High MediumA2 Medium Highest 57–62 Medium Medium High HighA9 Medium Highest 35–56 Medium High High Medium to

highD2 Medium Highest 54–61 Low Low High High to very

highD3 Medium High 54–61 Low Low High Very highH21 Medium High 36–54 Medium High High Medium to

highH26 Medium High 43–58 Medium Medium Very high HighP20 High High 28–37 Medium to high High Low Low to

mediumP21 High Highest 30–40 Medium Medium Medium MediumW1, W2 Highest Medium 50–64 Highest High Low Low to

medium

Source: Adapted from Tool Steels, American Iron and Steel Institute, 1978.

What methods available to improve the properties of steel?

Atomic structure----microscopic structure-----properties

Traditional methods--thermal treatment,adding of special admixtures, plastic

deformationNew methods—controlled solidification,laser irradiation, acoustic treatment etc.

Type of atomic structure

crystallinequasicrystal

amorphous

fractal

Aluminium and aluminium alloys

• Factors for selecting are:

1. High strength to weight ratio

2. Resistance to corrosion

3. High thermal and electrical conductivity

4. Ease of machinability

5. Non-magnetic

Magnesium and magnesium alloys• Magnesium (Mg) is the lightest metal.

• Alloys are used in structural and non-structural applications.

• Typical uses of magnesium alloys are aircraft and missile components.

• Also has good vibration-damping characteristics.

Copper and copper alloys

• Copper alloys have electrical and mechanical properties, corrosion resistance, thermal conductivity and wear resistance.

• Applications are electronic components, springs and heat exchangers.

• Brass is an alloy of copper and zinc.

• Bronze is an alloy of copper and tin.

Nickel and nickel alloys• Nickel (Ni) has strength, toughness, and

corrosion resistance to metals.

• Used in stainless steels and nickel-base alloys.

• Alloys are used for high temperature applications, such as jet-engine components and rockets.

Superalloys

• Superalloys are high-temperature alloys use in jet engines, gas turbines and reciprocating engines.

Titanium and titanium alloys

• Titanium (Ti) is expensive, has high strength-to-weight ratio and corrosion resistance.

• Used as components for aircrafts, jet-engines, racing-cars and marine crafts.

Refractory metals

• Refractory metals have a high melting point and retain their strength at elevated temperatures.

• Applications are electronics, nuclear power and chemical industries.

• Molybdenum, columbium, tungsten, and tantalum are referred to as refractory metal.

Other nonferrous metals

1. Beryllium

2. Zirconium

3. Low-melting-point metals: - Lead- Zinc- Tin

4. Precious metals: - Gold - Silver- Platinum

1. Shape-memory alloys (i.e. eyeglass frame, helical spring)

2. Amorphous alloys (Metallic Glass)

3. Nanomaterials

4. Metal foams

5. Magnetocaloric materias

6. Semi-solid metals

7. Multiferroics

8. Programmable materials

Advanced materials

Heat Treatment of Metals• Annealing

– Full annealing

– Normalising (faster rate of cooling)

– Recovery annealing (longer holding time, slower rate of cooling,)

– Stress relieving (lower temperature)

• Martensite formation in steel– Austenitizing (conversion to austenite)

– Quenching (control cooling rate

– Tempering (reduce brittleness)

Heat Treatment of Metals

• Precipitation hardening– Solution treatment (α-phase conversion)

– quenching

– precipitation treatment (aging)

• Surface hardening– Carburizing

– Nitriding

– Carbonitriding

– Chromizing and Boronizing

Heat Treatment of Steel

Precipitation Hardening

Solution treatment

Quenching

Precipitation treatment

Furnaces for Heat Treatment

• Fuel fire furnaces– gas– oil

• Electric furnaces– batch furnaces

• box furnaces - door

• car-bottom furnaces - track for moving large parts

• bell-type furnaces - cover/bell lifted by gantry crane

– continuous furnaces

Furnaces for Heat Treatment

• Vacuum furnaces

• Salt-bath furnaces

• Fluidized-bed furnaces

Some of the furnaces have special atmosphere requirements, such as carbon- and nitrogen- rich atmosphere.

Surface Hardening Methods

• Flame hardening

• Induction heating

• High-frequency resistance heating

• Electron beam heating

• Laser beam heating

Surface Hardening Methods

Inductionheating

High frequencyresistanceheating

Classification of Ceramics

• Ceramics– Traditional ceramics

– New ceramics

– Glass

Ceramics

• Traditional ceramics– clays: kaolinite

– silica: quartz, sandstone

– alumina

– silicon carbide

• New ceramics– oxide ceramics : alumina

– carbides : silicon carbide, titanium carbide, etc.

– nitrides : silicon nitride, boron nitiride, etc.

Glass

• Glass products– window glass

– containers

– light bulb glass

– laboratory glass

– glass fibers

– optical glass

• Glass ceramics - polycrystalline structure

Classification of Polymers

– Thermoplastics

– Thermosets

– Elastomers

Polymers

• Thermoplastics- reversible in phase by heating and cooling. Solid phase at room temperature and liquid phase at elevated temperature.

• Thermosets- irreversible in phase by heating and cooling. Change to liquid phase when heated, then follow with an irreversible exothermic chemical reaction. Remain in solid phase subsequently.

• Elastomers- Rubbers

Thermoplastics– Acetals

– Acrylics - PMMA

– Acrylonitrile-Butadiene-Styrene - ABS

– Cellulosics

– Fluoropolymers - PTFE , Teflon

– Polyamides (PA) - Nylons, Kevlar

– Polysters - PET

– Polyethylene (PE) - HDPE, LDPE

– Polypropylene (PP)

– Polystyrene (PS)

– Polyvinyl chloride (PVC)

Thermosets

• Amino resins

• Epoxies

• Phenolics

• Polyesters

• Polyurethanes

• Silicones

Elastomers• Natural rubber

• Synthetic rubbers– butadiene rubber– butyl rubber– chloroprene rubber– ethylene-propylene rubber– isoprene rubber– nitrile rubber– polyurethanes– silicones– styrene-butadiene rubber– thermoplastic elastomers

Classification of Composite Materials

– Metal Matrix Composites

– Ceramic Matrix Composites

– Polymer Matrix Composites

Composite Materials

• Metal Matrix Composites (MMC)Mixture of ceramics and metals reinforced by strong,

high-stiffness fibers

• Ceramic Matrix Composites (CMC)Ceramics such as aluminum oxide and silicon carbide

embedded with fibers for improved properties, especially high temperature applications.

• Polymer Matrix Composites (PMC)Thermosets or thermoplastics mixed with fiber

reinforcement or powder.

Composite Materials

1D fibre

Woven fabric

Random fibre

Composite Materials

Taxonomy of Materials Selection

Ashby,: Material Selection in Mechanical Design