1. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU 1 Metal Alloys ( 금속 합금 ) Associate Professor Su-Jin KimSu-Jin Kim School of Mechanical Engineering Gyeongsang National University

2. Metal Alloys Manufacturing Processes © 2013 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

3. Metal Alloys Manufacturing Processes © 2013 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/cm 3 ) as their base metal. Carbon steels (700W/kg) are least expensive of all metals while stainless steels (7,000W/kg) is costly.

4. Metal Alloys Manufacturing Processes © 2013 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 )

5. Metal Alloys Manufacturing Processes © 2013 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% PlainHSLA ( 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, costductility 1010 S10C 4310 SNCM10 1040 S40C 4340 SNCM40 1095 4190 KD11 304, 409 SUS304

6. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU 6 Steels AISI/SAE JIS/KSNomenclature( 조성 ) for steels 10xxSxxCPlain Carbon Steels ( 탄소강 ) 40xxSMoxxMo (.2 ~.3%) 41xxSCMxxCr (.80~1.1), Mo (.15~.25) 43xx SNCMxxNi (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%~)

7. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU Carbon steels ( 탄소강 ) Classified as low, medium and high: 1.Low-carbon steel or mild steel, C< 0.25%, bolts, nuts and sheet plates. 2.Medium-carbon steel, 0.25% ~ 0.60%, machinery, automotive and agricultural equipment. 3.High-carbon steel, C > 0.60%, springs, cutlery, cable. Ex) S10C S45C

8. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU Alloy steels ( 합금강 ) 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.

9. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU HSLA High-strength low-alloy steels ( 고강도 저합금강 ) Improved strength-to-weight ratio. Used in automobile bodies to reduce weight and in structural plate.

10. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU Tool & Die steels ( 공구강 금형강 ) Designed for high strength, impact toughness, and wear resistance at a range of temperatures. Ex) SKD11 SKD61 NAK80

11. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU Stainless steels Characterized by their corrosion resistance, high strength and ductility, and high chromium content( Cr >11%). Stainless as a film of chromium oxide protects the metal from corrosion. It resist oxidization and maintain mechanical integrity at high temperature (1000°C). JIS/KSCr(%)Heat treat Cor. Res. Mag netic Application SUS304austenite19XOOXAutomotive exhaust SUS409ferrite11XOOChem. proc. equip. SUS410martensitic12.5OOOKnifes

12. Metal Alloys Manufacturing Processes © 2013 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.krhttp://www.posco.co.kr

13. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU 13 Cast Irons ( 주철 ) Ferrous alloys with 3.0 ~4.5% C Low melting point  relatively easy to cast Generally brittle Cementite decomposes to ferrite + graphite Fe 3 C  3 Fe (  ) + C (graphite) : slow process

14. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU 14 Cast Irons Gray iron( 회주철 ) graphite flakes weak & brittle in tension stronger in compression excellent vibrational dampening wear resistant Ductile iron( 연주철 ) add Mg and/or Ce graphite as nodules not flakes matrix often pearlite – stronger but less ductile

15. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU 15 Cast Irons White iron( 백주철 ) < 1 wt% Si pearlite + cementite very hard and brittle Malleable iron( 가단주철 ) heat treat white iron at 800-900ºC graphite in rosettes reasonably strong and ductile

16. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU Cast Irons 급랭급랭 서랭 가열 가단주철 백주철 회주철 연주철

17. Metal Alloys Manufacturing Processes © 2013 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

18. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU 18 Nonferrous Alloys( 비철금속 ) NonFerrous Alloys Al Alloys -low  : 2.7 g/cm 3 -Cu, Mg, Si, Mn, Zn additions -solid sol. or precip. strengthened (struct. aircraft parts & packaging) Mg Alloys -very low  : 1.7g/cm 3 -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  : 4.5 g/cm 3 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

19. Metal Alloys Manufacturing Processes © 2013 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.

20. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU Aluminium alloys Factors for selecting Aluminum (Al) alloys are: High strength to weight ratio ( 2.7 g/cm 3 ) Resistance to corrosion High thermal and electrical conductivity Ease of machinability Non-magnetic Ex) A7075 A6061 A5052

21. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU Magnesium alloys Magnesium (Mg) is the lightest metal (1.7g/cm 3 ). It ignites easily. Typical uses of magnesium alloys are the frame of electric device like as smart phone.

22. Metal Alloys Manufacturing Processes © 2013 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 (Cr 15% Fr8%) alloys are used for high temperature applications, such as jet-engine components and rockets.

23. Metal Alloys Manufacturing Processes © 2013 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 …

24. Metal Alloys Manufacturing Processes © 2013 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/cm 3. Used as components for aircrafts, jet-engines, racing- cars and medical equipments. Ex) Ti-6AI-4V

25. Metal Alloys Manufacturing Processes © 2013 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.

26. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU 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 )

27. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU Special metals and alloys 1.Shape-memory alloys 2.Amorphous alloys 3.Nanomaterials 4.Metal foams

28. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU 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

29. Metal Alloys Manufacturing Processes © 2013 Su-Jin Kim, GNU Poongsan ( 풍산 ) Copper (Cu) : sheet & strips, tubes, rods, coin blanks, semiconductor leadframe