MATERIALS SCIENCE AND ENGINEERING I. Professor Catalin POPA, Dr.Eng.

Transcription

1 MATERIALS SCIENCE AND ENGINEERING I Professor Catalin POPA, Dr.Eng.

2 REFERENCES Download cursuri: Popa Catalin; password = PopaCatalin H. Colan, V. C. Cândea, s.a. - Ştiinţa materialelor Vol. 1, U.T. Press 2013; V. Cândea, C. Popa, T. Marcu - Atlas, structuri metalografice, U.T.Press 2012; V.Candea, C.Popa, N.Sechel, V.Buharu Clasificarea si simbolizarea aliajelor feroase si neferoase, UTPress, 2010; C. Popa, V. Cândea, V. Şimon, D. Lucaciu, O. Rotaru - Ştiinţa biomaterialelor. Biomateriale metalice, U.T.Press 2008; V.A.Serban, A.Raduta, Stiinta si ingineria materialelor, Timisoara, Ed. Politehnica 2012; H.Colan, s.a. Studiul Metalelor, Bucuresti, EDP 1983; D.Askeland Introduction to Materials Science, J.Wiley & Sons, 1993 C. Paul Materials Science and Engineering, ASM 1991 W. D. Callister, D. G. Rethwisch - Fundamentals of materials science and engineering, John Wiley and Sons, 2013; W. F. Hosford, Elementary materials science, ASM International 2013; D.L. Chung - Composite materials: science and applications : functional materials for modern technologies, Springer 2003;

3 INTRODUCTION TO MATERIALS SCIENCE Materials Science : Branch of Technical Sciences that studies the chemical composition structure ratio for engineering materials properties Age : as a science, after 1840 (optical microscope)

4 Nature / chemical composition of the material MATERIALS ENGINEERING Manufacturing technology Properties chemical physical mechanical Structure: macrostructure (1-50x) microstructure ( x) atoms scale ( 0.1 nm) USES

5 Content of the lecture course Introduction to Materials Science. Classes of engineering materials Properties of materials. Corrosion resistance. Corrosion protection methods. Interatomic bonding. Crystalline and amorphous structure. Crystallisation of metals. Plastic deformation of metals. Cold hardening, recrystallisation. Fracture. Alloys theory. Fe-C diagram. Unalloyed steels. Foundry cast irons. Heat treatments. Alloy steels. Non-ferrous alloys: Al and Cu based alloys. Polymers. Ceramics. Composite materials. Colours code: Red essential Blue very important Black normal importance

6 Properties of materials Mechanical Physical Chemical functional properties Technological Machinability Weldability Castability [ Formability ]

7 Materials Processing - Casting -

8 Materials Processing - Plastic forming - Forging (hot)

9 Materials Processing - Plastic forming - Rolling (hot)

10 Materials Processing - Plastic forming - Wire drawing

11 Materials Processing - Plastic forming - Deep drawing

12 Materials Processing - Machining- Turning

13 Materials Processing - Welding - Electric arc welding

14 Materials Processing - Powder aggregation-

15 Materials Processing - Additive manufacturing-

16 Effect of structure upon properties Ex.: graphite

17 Effect of structure upon properties Ex.: graphite fibers

18 Effect of structure upon properties Ex.: graphite fibers

19 Effect of structure upon properties Ex.: graphite fibers

20 Effect of structure upon properties Ex.: graphite nanotubes

21 Effect of structure upon properties Ex.: graphene Extremely light: surface of a football field 1g The strongest material: More than 130 times stronger than a high strength steel

22 CLASSES OF MATERIALS A. Origin natural (bone, rock, wood, proteins, etc.) synthesis Spider silk

23 CLASSES OF MATERIALS B NATURE Metals Ceramics Polymers Multimaterials Composites Multi-layered materials C USE Structural Functional Automotive Aerospace Electronics Optoelectronics Biomaterials Energy storage Sports equipment.

24 METALS 89 in periodic table electropositive character, common energy levels between conduction / valence bands; Practically not pure metals - alloys (the term is employed only for metals!) contain other elements, based on (a) metal Most used Fe, Al, Cu, Mg, Zn, Ti, Ni,... Metallic state: electric conductors, resistivity increases with temperature; thermal conductors; metallic shine; thermo-electronic effect;

25 METALS

26 METALS: ADVANCED ALLOYS Super-light alloys Shape-memory alloys Superalloys

27 CERAMICS Definition: Materials containing anorganic compounds, without metallic character. General: contain metallic elements, combined with strong non-metallic elements (O, Cl, F,...) Exceptions: C, B Classification: A. Classic (porcelain, clay, usual glass,...) Engineering (alumina, zirconia, TiN,...) B. Amorphous glasses Crystalline

28 CRYSTALLINE ENGINEERING CERAMICS

29 ENGINEERING GLASSES

30 POLYMERS Definition: Macro-molecular organic materials, made of long atom chains (C + H, O, N) (M = Da) Classification: thermoplasts (plastics) thermosets elastomers

31 POLYMERS

32 POLYMERS

33 POLYMERS

34 COMPOSITES Materials composed of: matrix (majority of volume, maintains part s shape) + reinforcing constituent Classification: A. Matrix material Polimeric (Organic) Metallic Ceramic B. Shape of reinforcing constituent Fibres long short Fabric Particles

35 COMPOSITES

36 ADVANCED COMPOSITES Boeing 787

37 MULTILAYERED MATERIALS Materials composed of layers of different materials, strongly bonded, that behave as a single material Example: skis

38 PROPERTIES OF MATERIALS

39 PHYSICAL PROPERTIES Density [kg/m 3 ] m /V metals: Li(0.53) Mg(1.74) Al(2.7) Fe(7.8) Os(22.5) ceramics: Grafit(2.28).WC( ) polymers: values related to water [kg/m 3 x 10-3 ] Electrical conductivity σ Metals: conductors Ag Cu Au Al -... Mn Ceramics: insulators (in general); exceptions: C, semiconductors, superconductors Polymers: insulators (in general) exceptions: conductive polymers Thermal conductivity λ = thermal energy transferred through the material to increase the temperature with 1K at a distance of 1m for a time of 1s; Similar to σ (in general) metals: conductors Au Cu Ag Al -... ceramics, polymers: insulators

40 PHYSICAL PROPERTIES Thermal expansion coefficient α l l0 1 t (approx.) In general: polymers / metals > ceramics exceptions: invar alloys Magnetic properties χm = magnetic susceptibility; μ = magnetic permeability; Materials: dia-magnetic (χm < 0) (Cu, Ag, Au,...) para-magnetic (χm >0, mic) (Feγ, Al, Ti,...) ferro-magnetic (χm >>0) (Feα, Ni, Co, under Curie temperature)

41 Glossary Casting = turnare; Plastic forming = deformare plastica (proces); Forging = forjare; Rolling = laminare; Deep drawing = ambutisare; Wire drawing = trefilare; Welding = sudare; Machining = aschiere; Turning = strunjire; Composite = compozit; Part = piesa; Strength = rezistenta (mecanica); Stiffness = rigiditate; Toughness = tenacitate; Alloy = aliaj; Steel = otel; Multilayered material = multimaterial stratificat; Engineering ceramic = ceramica tehnica Thermoplast = termoplast; Thermoset = termorigid; Reinforcing constituent = constituent de armare;