CIV203 MATERIALS SCIENCE PART_1

Transcription

1 CIV203 MATERIALS SCIENCE PART_1 Asst.Prof.Dr. Mert Yücel YARDIMCI Gediz University Deparment of Civil Engineering 1

2 CIV203 MATERIALS SCIENCE /Fall Instructor : Assist Prof.Dr. Mert Yücel YARDIMCI Tuesday (Group A) & Wednesday (Group B) 09:00 12:00 Class : D-Z06 Office Office hours : upon request mert.yardimci@gediz.edu.tr : Block F (Construction Materials Lab.) 2

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4 CIV203 MATERIALS SCIENCE Homeworks Mid-term exam : 40 % Final exam : 50 % : Quizzes and homeworks may be assigned (10% total if any) Exams will be the combination of multiple-choice fill-in-the-blank true/false short answer and in some cases calculation types of questions. Copying is not permitted! Late homework is not accepted! 4

5 Textbook William D. Callister & David. G. Rethwisch, Materials Science and Engineering: An Introduction, John & Wiley, Turhan Y. Erdoğan, Mustafa Tokyay, İ.Özgür Yaman and Sinan T. Erdoğan, Introduction to Materials Science for Civil Engineers METU Press Publishing Company, 2010, Ankara, Turkey. 5

6 CIV203 MATERIALS SCIENCE Lecture notes (power-point presentations in pdf format) can be downloaded from The presentations are the combinations of two textbooks listed in the previous slide. Exams : Closed-books and closed-notes! Pre-readings on the subjects will be learned each week are required! Pre-readings will be announced later! 6

7 Course Content Prt-sc view of syllabus 7

8 Course Objectives Inform the students about chemical, physical and mechanical properties of engineering materials such as metals, ceramics, polymers and composites. Learn the properties of materials. Learn the internal structure of materials. Learn how the internal structure of a material affects its properties. Metals : Metallic bonding ductility Ceramics : Ionic and covalent bods brittleness Plastics : Covalent and Van der Waals bonds moisture resistance 8

9 Expected Outcomes Know about the atomic structure & internal structure of materials. Know about the basic engineering properties (strength, ductility, impact resistance, etc.) of engineering materials (metals, ceramics, polymers, composites). Know about the relationship between atomic structure and engineering properties of materials. Understanding the role of basic properties of materials on material behavior. The ability to apply knowledge of material properties for selecting an appropriate material in engineering design (you are expected to use this info in your future career!) 9

10 CHAPTER I INTRODUCTION 10

11 What do Engineers do? Design and Build... As Civil Engineers we design and build civil structures (residental buildings, hospitals, dams, roads, towers,...) Materials Science and Engineering forms the bedrock for the engineering disciplines because the structures, components, and devices that engineers design and use must be made out of something, and that is a material. 11

12 The properties of the materials that are available define and limit the capabilities that the device or structure can have, and the techniques that can be used to fabricate it. Reinforced Concrete Bridges... ~5-10 m in span Prestressed Concrete Bridges... ~ m in span Steel Bridges... ~ m in span 12

13 Selecting the best material is usually a difficult task, requiring tradeoffs between different material properties (including cost) Typical cost of a residential building: 65-75% materials cost 5% technical personel Rest is the labor cost 13

14 Therefore, an appreciation of the important materials characteristics, the connection between the behavior of the material in its intended design setting, and the stuff the object is made from (and how it is made) is important to every engineer, even if they will never create a new material but simply choose from standard and widely available ones. 14

15 As civil engineers our job is to: To make sure that the structure is functional during its service life (it should be strong) To make sure that the structure should withstand the environment (it should be durable) To make sure that the structure is aesthetic and economic (it should be feasible) We need to know the properties of constructional materials. Physical, chemical and mechanical properties Manufacturing processes Its behavior in its final form 15

16 The service life of a civil engineering structure does not ONLY depend on How good its design is How good its labor is You have to consider other factors such as: How good the material that you pick is How good the quality control is How you maintain the structure! Think about the maintenance requirements of your car! your house! 16

17 Why do we need to know materials? Every engineer, whether civil, mechanical, chemical or electrical, will at some point deal with a design problem involving materials. Examples might include the superstructure of a building, an oil refinery component, a transmission gear, or an integrated circuit chip. Materials Science: The study of the nature, behavior and use of materials. 17

18 General Properties of Materials Mechanical Define the behavior of the materials under loads. (Strength, elasticity, plasticity, ductility, hardness, etc.) Physical Density, porosity, moisture content, shape, surface texture, etc. Chemical Oxide or compound composition Physico-chemical Shrinkage, swelling Thermal Conductivity Acoustical Sound transmission or absorption Optical 18

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20 Classification of Civil Engineering Materials This classification can be done in so many different ways: According to their state According to their chemical composition and internal structure According to their intended use According to their mechanical behavior 20

21 1. According to Their State Gases (CO 2, O 2 ) Liquids (Water, Chemical Admixtures) Solids (Concrete, Steel) Semi-solids (Fresh Pastes, Mortar, Concrete) Fresh concrete Solid steel 21

22 2. According to Their Chemical Composition and Internal Structure Metals Metallic bond Ferrous (Iron, steel) Non-ferrous (Aluminum) Polymers Long chain molecules Natural (rubber, resin, wood) Artificial (plastics) Ceramics Alumino silicates Structural clay products Porcelains Composite Materials combination of several materials Concrete Cement sandstone Reinforced Composite Materials Reinforced concrete Fiber reinforced plastics 22

23 3. According to Their Intended Use Structural Materials (concrete, steel, wood) Architectural Detailing Materials (glass, paint, heat and sound insulators) Preservatives (wall paint) But some materials fall into all of the above groups for example wood. Load carrying member Architectural Coating of chipboard 23

24 Load Load Load 4. According to Their Mechanical Behavior Elastic Materials They deform under some load and when the load is removed they return back to their original position Plastic Materials They deform under some load, but when the load is removed there will be some permanent deformation Viscoelastic Materials The load-deformation depends on the rate of loading Permenant def. Fast loading Deformation Deformation Slow loading Deformation 24

25 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES Metals are composed of one or more metallic elements (such as iron, aluminum, copper, titanium, gold, and nickel), and often also nonmetallic elements (for example, carbon, nitrogen, and oxygen) in relatively small amounts. Atoms in metals and their alloys are arranged in a very orderly manner, and in comparison to the ceramics and polymers, are relatively dense. These materials are relatively stiff and strong, yet are ductile (i.e., capable of large amounts of deformation without fracture), and are resistant to fracture, which accounts for their widespread use in structural applications. 25

26 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES Metallic materials have large numbers of non-localized electrons; that is, these electrons are not bound to particular atoms. Many properties of metals are directly attributable to these electrons. For example, metals are extremely good conductors of electricity and heat, and are not transparent to visible light; a polished metal surface has a lustrous appearance. 26

27 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES Ceramics are compounds between metallic and nonmetallic elements; they are most frequently oxides, nitrides, and carbides. Ceramic materials include aluminum oxide (or alumina,al2o3), silicon dioxide (or silica, SiO2), silicon carbide (SiC), silicon nitride (Si3N4), and, in addition, what some refer to as the traditional ceramics those composed of clay minerals (i.e., porcelain), as well as cement, and glass. 27

28 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES With regard to mechanical behavior, ceramic materials are relatively stiff and strong stiffnesses and strengths are comparable to those of the metals. Ceramics are typically very hard. On the other hand, they are extremely brittle (lack ductility), and are highly susceptible to fracture. These materials are typically insulative to the passage of heat and electricity (i.e., have low electrical conductivities) 28

29 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES Ceramics are more resistant to high temperatures and harsh environments than metals and polymers. With regard to optical characteristics, ceramics may be transparent, translucent, or opaque. 29

30 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES Polymers include the familiar plastic and rubber materials. Many of them are organic compounds that are chemically based on carbon, hydrogen, and other nonmetallic elements (O,N, and Si). Polymers have very large molecular structures, often chain-like in nature that have a backbone of carbon atoms. 30

31 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES Some of the common and familiar polymers are polyethylene (PE), nylon, polyvinyl chloride (PVC), polycarbonate (PC), polystyrene (PS), and silicone rubber. 31

32 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES Polymer materials typically have low densities, mechanical characteristics are generally dissimilar to the metallic and ceramic materials they are not as stiff nor as strong as these other material types. However, on the basis of their low densities, many times their stiffnesses and strengths on a per mass basis are comparable to the metals and ceramics. 32

33 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES In addition, many of the polymers are extremely ductile and pliable (i.e., plastic), which means they are easily formed into complex shapes. In general, they are relatively inert chemically and unreactive in a large number of environments. One major drawback to the polymers is their tendency to soften and/or decompose at modest temperatures, which, in some instances, limits their use. Furthermore, they have low electrical conductivities and are nonmagnetic. 33

34 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES A composite is composed of two (or more) individual materials, which come from the metals, ceramics, and polymers. The design goal of a composite is to achieve a combination of properties that is not displayed by any single material, and also to incorporate the best characteristics of each of the component materials. 34

35 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES A large number of composite types exist that are represented by different combinations of metals, ceramics, and polymers. 35

36 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES Concrete Metallic or polymer fibers Wood and bone are also composite materials. The other composties are called manmade composites. 36

37 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES One of the most common and familiar composites is glass fiber reinforced concrete (GFRC), in which glass fiber textiles are embedded within a very flowable cement slurry. 37

38 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES Heydar Aliyev Center Baku/Azerbijan Completed in 2013 Glass Fibre Reinforced Concrete (GFRC) and Glass Fibre Reinforced Polyester (GFRP) cladding panels. 38

39 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES Carbon fiber in textile form Carbon fiber polymer product 39

40 General properties of main materials METALS CERAMICS POLYMERS COMPOSITES The glass fibers are relatively strong and stiff (but also brittle), whereas the polymer is ductile (but also weak and flexible). Thus, the resulting fiberglass is relatively stiff, strong, flexible, and ductile. In addition, it has a low density. 40

41 COMPARISON OF SOME TECHNICAL PROPERTIES OF MAIN TYPES OF MATERIALS Back to metals Back to polymers Back to composites 41

42 COMPARISON OF SOME TECHNICAL PROPERTIES OF MAIN TYPES OF MATERIALS Back to metals Back to ceramics Back to polymers Back to composites 42

43 COMPARISON OF SOME TECHNICAL PROPERTIES OF MAIN TYPES OF MATERIALS Back to metals Back to ceramics Back to polymers Back to composites 43

44 COMPARISON OF SOME TECHNICAL PROPERTIES OF MAIN TYPES OF MATERIALS Back to metals Back to ceramics Back to composites 44

45 COMPARISON OF SOME TECHNICAL PROPERTIES OF MAIN TYPES OF MATERIALS Back to metals Back to ceramics Back to polymers 45

46 Homeworks Read carefully Chapter 1 Introduction of Textbook 1 & 2. References W. D. Callister & D. G. Rethwisch, Materials Science and Engineering: An Introduction, John & Wiley, T.Y. Erdoğan, M. Tokyay, İ.Ö. Yaman and S.T.Erdoğan, Introduction to Materials Science for Civil Engineers METU Press Publishing Company, 2010, Ankara, Turkey. 46