Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

1

Metal Alloys (금속 합금)

Professor Su-Jin Kim

Mechanical Engineering

Gyeongsang National University

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

OCW

Steel: Iron, Carbon, Stainless, Manganese, Titanium steel

https://youtu.be/omGKUKwJPB8 Stainless: https://youtu.be/gLNltMtBjc8

History: https://youtu.be/7E__zqy6xcw

POSCO: https://youtu.be/YK2pvmVpoVM

Copper, Brass, Bronze: https://youtu.be/ysInnHOoouc

Aluminum: https://youtu.be/yn9qhQSMCRk

Titanium: https://youtu.be/CLLFNmTVmpQ 25min

Aluminum & Titanium: https://youtu.be/R5iK95ZeL-E

Alloys: https://youtu.be/X7b8_9wAREE

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

OCW

Steel C.A.S.T : https://youtu.be/VBzmGyWeNzo

Carbon Steel: https://youtu.be/JTu-Zz5jalc

Alloy Steel: https://youtu.be/dpm_uoXzwXE

Stainless Steel: https://youtu.be/TILs8w6myoU

Tool Steel: https://youtu.be/-fZQ9ElnymI

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

KOCW

철강

http://www.kocw.net/home/cview.do?lid=c2305cd4e3f38472

비철금속

http://www.kocw.net/home/cview.do?lid=e83e3461feb3633f

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Metal Alloys(금속)

Metal Alloy

(금속합금)

Ferrous

(철)

Nonferrous

(비철금속)

Steels

(강)

C<1.4%

Cast Irons

(주철)

3.0~4.5%

Copper

alloy

Aluminum

alloy

…

alloy

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Ferrous Alloys (철)

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

• Alloys contain iron Fe (density 7.9 g/cm3) as their base metal.

• Carbon steels (700W/kg) are least expensive of all metals while stainless steels (7,000W/kg) is costly.

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Irons

Liquid, L

Austenite, γ

Ferrite, α

Cementite, Fe3C

α+γ

α+Fe3C

γ+Fe3C

γ+L

0 1 2 3 4 5 6 6.7 400

Composition (wt% C)

Tem

pe

ratu

re (

ºC)

600

800

1000

1200

1400

1600

2.14 4.3

0.022

Cast Iron Steel

0.76 727 ºC

1147ºC

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Steels (강)

Composition and processing are controlled in a manner that is suitable for different applications.

Several elements are added to steels for

Strength(강도), Hardness(경도), Toughness(인성)

Hardenability(경화성), Wear resistance(내마모성)

Workability(가공성), Weldability(용접성), Machinability(절삭성)

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Steels Carbon steel

(탄소강)

High alloy steel

(고합급강)

Low carbon

(저탄소강) C < .25 %

Med carbon

(중탄소강) .25-.60%

High carbon

(고탄소강) .60-1.40%

Plain HSLA

(고강도) Plain

Heat

Treatable

(열처리)

Plain Tool

(공구)

Stainless

(스테인리스)

auto struc. sheet

bridges towers press. vessels

crank shafts bolts hammers

pistons gears wear applic.

wear applic.

drills saws dies

high T

turbines furnaces corrosion resistant

strength, hardenability, cost ductility

1010

S10C

4310

SNCM10

1040

S40C 4340

SNCM40 1095 4190

KD11

304, 409

SUS304

Metal Alloys

Manufacturing Processes

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10

Steels

AISI/SAE JIS/KS Nomenclature(조성) for steels

10xx SxxC Plain Carbon Steels (탄소강)

40xx SMoxx Mo (.2 ~ .3%)

41xx SCMxx Cr (.80~1.1), Mo (.15~.25)

43xx SNCMxx Ni (1.65 ~ 2.0), Cr (.4 ~ .9), Mo (.2~.3)

where xx is % C x 100

Ex) 1045 S45C – Plain Carbon Steel with 0.45 % C

Stainless Steel 304 SUS304 Cr (11%~)

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Carbon steels (탄소강)

Low-carbon steel or mild steel, C< 0.25%, bolts, nuts and sheet plates.

Medium-carbon steel, 0.25% ~ 0.60%, machinery, automotive and agricultural equipment.

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

S10C S45C

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Alloy steels (합금강)

• Steels + alloying elements: Cr(hardness, toughness), Co(hot hardness), Mn(hardness, strain), Mo(strength), Ni(strength, corrosion resistance), W(hardness, heat resistance), V(strength). ex) SCM40, SNCM40, SCV50

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

• HSLA (High-strength low-alloy steels, 고강도 저합금강) used in automobile bodies and structural plate.

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Tool steels (공구강)

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

SKD11 SKD61 Stamping Die

KP4, KP4M, NAK80 Plastic injection Mold

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Stainless steels

A chromium oxide film protects the steel from corrosion. (+ Cr >11% + Ni ...)

Good corrosion resistance and mechanical properties at high temperature (1000°C).

JIS/KS Cr(%) Heat treat

Cor. Res.

Magnetic

Application

SUS304 austenite 19 X OO X Automotive exhaust

SUS409 ferrite 11 X O O Chem. proc. equip.

SUS410 martensitic 12.5 O O O Knifes

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Posco

• Hot rolled steel, Steel plate, Wire rod, Cold rolled steel, Electric steel, Stainless steel, Galvanized steel, Titanium

Posco http://www.posco.co.kr

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Cast Irons (주철)

• Ferrous alloys with 3.0 ~4.5% C, 1~3% Si

• Cementite decomposes to ferrite + graphite

Fe3C 3 Fe () + C (graphite) : slow process

• Low melting point relatively easy to cast

• Generally brittle

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Cast Irons

Gray cast iron(회주철)

• graphite flakes brittle

• weak in tension, stronger in compression

• excellent vibrational dampening

• most commonly used cast iron: engine cylinder blocks, flywheels, gearbox cases, machine-tool bases

Ductile cast iron(구상흑연주철,연주철)

• add Mg and/or Ce

• graphite as nodules not flakes

• strong and ductile

• gears, camshafts, crankshafts

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Cast Irons

White cast iron(백주철)

• fast cooling(급랭) and lower Si content

• pearlite + cementite Fe3C

• high hardness but brittle

• Bearing surfaces

Malleable cast iron(가단주철)

• heat treat(가열) white iron at 900°C

• graphite in rosettes

• reasonably strong and ductile

• Axle bearings, track wheels, crankshafts

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Cast irons

• 대한주조공업 http://daesp.co.kr

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Nonferrous Alloys (비철금속)

More expensive than ferrous metals.

Applications:

• aluminium for aircraft bodies

• copper wire

• titanium for jet-engine turbine blades

• tantalum for rocket engines

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

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Nonferrous Alloys(비철금속)

NonFerrous Alloys

• Al Alloys -low r: 2.7 g/cm3

-Cu, Mg, Si, Mn, Zn additions -solid sol. or precip. strengthened (struct.

aircraft parts & packaging)

• Mg Alloys -very low r : 1.7g/cm3

-ignites easily - smartphone

• Refractory metals -high melting T’s -Nb, Mo, W, Ta • Noble metals

-Ag, Au, Pt - oxid./corr. resistant

• Ti Alloys -relatively low r: 4.5 g/cm3

vs 7.9 for steel -reactive at high T’s - space applic.

• Cu Alloys Brass: Zn is subst. impurity (costume jewelry, coins, corrosion resistant) Bronze : Sn, Al, Si, Ni are subst. impurities (bushings, landing gear) Cu-Be : precip. hardened for strength

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Copper alloys

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

• Applications are electronic components, springs and heat exchangers.

Brass(황동) is an alloy of copper and zinc (Zn 30%). Applications are costume jewelry, coins, corrosion resistant.

Bronze(청동) is an alloy of copper and tin (Sn 10% , Al, Si, Ni). Applications are bushings, landing gear.

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Aluminium alloys

• High strength to weight ratio ( 2.7 g/cm3)

• Resistance to corrosion Al2O3 surface layer, Anodising

• High thermal and electrical conductivity

• Ease of machinability, Non-magnetic, Light reflection

• Age hardening

Ex) A7075 A6061 A5052

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Magnesium alloys

• Magnesium (Mg) is the lightest metal (1.7g/cm3).

• It ignites easily. Combustible.

• Typical uses of magnesium alloys are the frame of electric device like as smart phone.

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Titanium alloys

• Titanium (Ti) is expensive, has high strength-to-weight ratio and corrosion resistance. Relatively low density 4.5 g/cm3.

• Used as components for aircrafts, jet-engines, racing-cars and medical equipment.

• Ex) Ti-6AI-4V

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Nickel alloys

• Nickel (Ni) has strength, toughness, and corrosion resistance to metals.

• Used in stainless steels and nickel-base alloys at chemical and food processing industry (Nikel200).

• Inconel 600 (Ni 72% Cr 15% Fr8%) alloys are used for high temperature applications, such as jet-engine components and rockets.

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Superalloys

• Superalloys (초합금) are high-temperature alloys use in jet engines and gas turbines.

Ex) IN-100 -102, Inconel 625 718, MAR-M 200 432 …

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Refractory metals

• Refractory metals (고용융점 금속) 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 (Nb, Mo, W, Ta) are referred to as refractory metal.

Metal Alloys

Manufacturing Processes

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Other nonferrous metals

1. Beryllium (Be)

2. Zirconium (Zr)

3. Low-melting-point (저 용융점) metals: - Lead (Pb, 납) - Zinc (Zn, 아연) - Tin (Sn, 주석)

4. Precious metals (귀금속): - Gold (Ag, 금) - Silver (Au, 은) - Platinum (Pt, 백금)

Metal Alloys

Manufacturing Processes

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Korea Zink (고려아연)

• Zinc (Zn) : Galvanized steel plate(pipe, wire), color steel plate, automobile part, machine/electronic part, anti-corrosion paint

• Lead (Pb) : Automobile and industrial battery, electric wire coating, radiation shielder

• Copper, God, Silver, Indium, nickel, bismuth, antimony trioxide, palladium, platinum, cadmium, gallium, germanium, tellurium, cobalt

Metal Alloys

Manufacturing Processes

© Su-Jin Kim, GNU

Poongsan (풍산)

• Copper (Cu) : sheet & strips, tubes, rods, coin blanks, semiconductor leadframe