JF302 Material Technology: Chapter 1

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Chapter 1 material structure..khusus untuk pelajar mekanikal politeknik.. ;)

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JF302 Material Technology: Chapter 1

  1. 1. LOGO CHAPTER 1 : MATERIAL STRUCTURE © Mechanical Engineering Department
  2. 2. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Introduction • structure of a material give a major impact on its characteristic and behavior • it can help to control and predict the behavior and performance of materials in various manufacturing processes • materials can be found in metal and non-metal • the basis for materials formulation • consists from arrangement of atoms that we called crystalline
  3. 3. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Content 1 Material Structure 2 The Periodic Table 3 Crystal Structure 4 Atom Bonding
  4. 4. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Material Structure  can determine the arrangement of atoms, the density and related properties  can control the material properties  a material come from the internal structure of materials  internal structure of materials involves how relationship the atoms with another atoms to form crystals, molecule and micro structures
  5. 5. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Material Structure – cont…  crystal is a homogenous solid formed by a repeating, three-dimensional pattern of atoms, ions, or molecules and having fixed distances between constituent parts.  molecule is the smallest particle of a substance that retains the chemical and physical properties of the substance and is composed of two or more atoms; a group of like or different atoms held together by chemical forces.  micro structure is a structure separated by grain boundaries and requires expansion to be seen
  6. 6. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Material Structure – cont… Matter Impure Substances (Mixtures) Pure Substances Elements Atoms Compounds Homogeneous Mixtures Molecules Molecules Ions Heterogeneous Mixtures
  7. 7. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Matter  Matter is a general term for the substance of which all physical objects consist  includes atoms and other substance which have mass  any object that has mass and occupies volume  all materials whether solid, liquid or gas in the earth is a matter  substances of matter may build the :  Atom  Molecule  Ion
  8. 8. CHAPTER 1 : MATERIAL STRUCTURE Example JF302 – MATERIAL TECHNOLOGY 1
  9. 9. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Elements  consisting of small substances which can not be subdivided  a combination of two or more similar atoms  in a pure condition Silver Zinc Cooper
  10. 10. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Atom  a basic unit of matter  can not be created and destroyed  the substances that make up all material in the form of solid, liquid or gas  small size, but it has a weight and its own characteristics  consists of three basic substances such as protons (+), neutrons (neutral) and electrons (-)  An atom is classified according to the number of protons and neutrons in its nucleus: the number of protons determines the chemical element, and the number of neutrons determines the isotope of the element.
  11. 11. CHAPTER 1 : MATERIAL STRUCTURE Atom – cont…  protons and neutrons contained in the nucleus of an atom, while the electrons are arranged in shells around the nucleus Elektron Petala / orbit / kelompang 1 Petala 2 Petala 3 Nukleus yang mengandungi proton dan neutron JF302 – MATERIAL TECHNOLOGY 1
  12. 12. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Molecules  is the smallest particle of a substance that retains the chemical and physical properties of the substance  A molecule is formed when two or more atoms join together chemically
  13. 13. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Compounds  A compound is a molecule that contains at least two different elements  compound exist naturally or artificial  it can be separated into simpler substances by chemical reactions Benzena (C6H6) Ammonia (NH3) Water (H2O)
  14. 14. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 What is the difference between a compound and a molecule? Compound Molecule A compound is a molecule that contains A molecule is formed when two or more at least two different elements atoms join together chemically Water (H2O), carbon dioxide (CO2) and methane (CH4) are compounds because each is made from more than one element Molecular hydrogen (H2), molecular oxygen (O2) and molecular nitrogen (N2) are not compounds because each is composed of a single element * All compounds are molecules but not all molecules are compounds
  15. 15. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Mixtures  combination of two or more atoms of different types, but are not combined chemically  Mixture refers to the physical combination of two or more substances the identities of which are retained  Mixtures can be either homogeneous or heterogeneous
  16. 16. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 The difference of a homogenous and a heterogeneous mixture Homogenous Heterogeneous a mixture of more than one a mixture of more than one substance that appears to be substance in which there are all one substance; also called a visible, different parts solution have uniform composition and properties throughout aren't uniform in composition and properties throughout unseparable by mechanical methods separable by mechanical methods Example : air, alloy, paint, margarine, blood etc Example : concrete, sand, pizza, soil, muddy water etc
  17. 17. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 The Periodic Table  In 1869, Dmitri Mendeleev developed the first periodic table based on atomic mass:  (atomic mass= #protons+#neutrons in the nucleus of the atom)  In 1913, Thomas Moseley developed the modern periodic table based on atomic number  (atomic number= #protons in the nucleus of the atom)  The modern periodic table is arranged in columns and rows  Columns go up and down  Rows go from left to right
  18. 18. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 The Periodic Table – cont… Groups or Families  Columns are called: Groups or Families  There are 18 groups or families in the periodic table  Elements in the same group or family have the same number of valence electrons  Valence electrons are the number of electrons in the outer most energy level
  19. 19. CHAPTER 1 : MATERIAL STRUCTURE Elements within a group have similar physical and chemical properties Example Na (2,8,1) and K (2,8,8,1) are both in Group 1 JF302 – MATERIAL TECHNOLOGY 1 All have the same number of electrons in their outermost or valence shells
  20. 20. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 The Periodic Table – cont… Let’s look at a few elements… Fluorine Lithium Hydrogen Argon Helium
  21. 21. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 The Periodic Table – cont… Group Number Group Name Valence Number 1 Alkali Metals 1 2 Alkaline Earth Metals 2 3 -12 Transitional Elements 1 or 2 13 Boron family 3 14 Carbon family 4 15 Nitrogen family 5 16 Oxygen family 6 17 Halogens 7 18 Noble Gases 8
  22. 22. CHAPTER 1 : MATERIAL STRUCTURE The Periodic Table – cont… Groups or Families  Group 1 has 1 valence electron  2 2  13 3  14 4  15 5  16 6  17 7  18 8  *Groups 3-12 do not follow this pattern JF302 – MATERIAL TECHNOLOGY 1
  23. 23. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 The Periodic Table – cont… Periods  Periods are the portion of the periodic table that go from up to down.  There are 7 periods in the periodic table.  All elements in the same period, have the same number of energy levels.  Energy levels are where the electrons are located
  24. 24. CHAPTER 1 : MATERIAL STRUCTURE The Periodic Table – cont… JF302 – MATERIAL TECHNOLOGY 1
  25. 25. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 ELECTRON CONFIGURATION  is the arrangement of electrons of an atom, a molecule, or other physical structure  knowledge of the electron configuration of different atoms is useful in understanding the structure of the periodic table of elements  each shell can only be filled by the number of electrons only  if a shell has been fully filled, the electrons have to be filled in the next shell  electrons will occupy the orbit closest to the nucleus before occupying another shell
  26. 26. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 THE PERIODIC TABLE FEATURES  chemical properties of an atom depends on the number of electrons in the outer shells of atoms, called atomic valence  elements have the same number of electrons in the outer shell will be included in the same group  each period have the same number of shells  when the electron is increased, the properties of the metal elements become less and less
  27. 27. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 USE OF THE PERIODIC TABLE  know, understand and forecast chemistry and physics properties of an element  easy to remember the characteristics of a particular element in the position of the periodic table  recognize and identify the specific elements of different groups  make a study more about the elements of the existing and new found
  28. 28. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Crystal Structure Crystal Structure Crystalline Amorphous is a particles are arranged in order and formed as a result of the slow cooling is a particles are randomly arranged and formed as a result of rapid cooling
  29. 29. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Crystal Structure – cont…  consists from arrangment of atoms in a three-dimensional  in solidification of atomic process, molten metal will react with each other and organize their respective positions in a uniform and orderly  this arrangement is called space lattice process  The types of crystal structures 1. Simple Cubic (SC) 2. Body-Centered Cubic (BCC) 3. Face-Centered Cubic (FCC) 4. Hexagonal-Close Packed (HCP)
  30. 30. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 SIMPLE CUBIC (SC)  the simple cubic unit cell is a cube (all sides of the same length and all face perpendicular to each other) with an atom at each corner of the unit cell  there are eight atoms at the corners and each such atom makes  a simple cubic unit cell has : 8 (at corners) x 1/8 = 1 atoms
  31. 31. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 EXAMPLE OF SIMPLE CUBIC (SC) Sodium Chloride
  32. 32. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 BODY-CENTERED CUBIC (BCC)  this type of unit cell has eight atoms at corners and one at the body center.  each corner atom makes 1/8 contribution and the atom at the body center belongs only to the particular unit cell.  a body-centered cubic unit cell has : 8 (at corners) x 1/8 + 1 (at body center) x 1 = 2 atoms
  33. 33. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 EXAMPLE OF BCC Chromium Iron Sodium Tungsten
  34. 34. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 FACE-CENTERED CUBIC (FCC)  a face centered cubic unit cell has one atom at each corner and one atom at each face center  being shared by two unit cells and making a contribution of only ½ to a particular unit cell  a face-centered cubic unit cell has : 8 (at corners) x 1/8 + 6 (at face centers) x ½ = 4 atoms
  35. 35. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 EXAMPLE OF FCC Silver Gold Copper Aluminum
  36. 36. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 HEXAGONAL-CLOSE PACKED (HCP)  the unit cell for the hexagonal closest-packed structure has a diamond-shaped or hexagonal base with sides of equal length  the base is perpendicular to the longest side of the unit cell  an atom is centered on each corner of the unit cell  a hexagonal closest-packed unit cell has : 12 (at corners) x 1/6 + 2 (at face centers) x ½ + 6 (at sides) x ½ = 6 atoms
  37. 37. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 EXAMPLE OF HCP Titanium Zinc Cobalt
  38. 38. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 ATOMIC BONDING BONDING Ionic Metallic Covalent
  39. 39. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 IONIC BONDS  also called electrovalent bond  a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions  formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal  a bond forms when one or more electrons are transferred from one neutral atom (metal) to another atom (non-metal)  the two types of ion are held together by electrostatic forces
  40. 40. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 EXAMPLE : Natrium Chloride (NaCl)
  41. 41. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 EXAMPLE : Magnesium Chloride (MgCl2)
  42. 42. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 COVALENT BONDS  form when atoms share one or more pairs of electrons  usually happens between nonmetals  can classified into single, double, and triple covalent bond with respect to mutual sharing of one, two, and three bonds respectively
  43. 43. CHAPTER 1 : MATERIAL STRUCTURE EXAMPLE : Water (H2O) JF302 – MATERIAL TECHNOLOGY 1
  44. 44. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 EXAMPLE : Oxygen Molecule (O2)
  45. 45. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 METALLIC BONDS  formed between two or more metal cations  metal atoms release their valence electrons into a sea of valence electrons shared by all of the metal atoms  the attraction of these free electrons to the metal cations is called a metallic bond
  46. 46. CHAPTER 1 : MATERIAL STRUCTURE EXAMPLE : A GROUP 2 METAL Each atom releases its two valence electrons into a pool of electrons to be shared by all of the metal atoms. JF302 – MATERIAL TECHNOLOGY 1
  47. 47. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Metallic Bonding explains some physical properties of Metals Metals are ductile – they can be drawn into wires.
  48. 48. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Metallic Bonding explains some physical properties of Metals Metals are good electrical conductors because the valence electrons are free to travel
  49. 49. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Atomic View of Metallic Bonding • Bonding in metals is not rigid. • As a metal is struck by a hammer, the atoms slide through the electron sea to new positions while continuing to maintain their connections to each other. • The same ability to reorganize explains why metals can be pulled into long, thin wires.
  50. 50. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Metal atoms are arranged in very compact and orderly patterns
  51. 51. CHAPTER 1 : MATERIAL STRUCTURE JF302 – MATERIAL TECHNOLOGY 1 Compare and Contrast Types of Bonding Similarities Differences  Metallic and ionic bonding involve electrostatic attractions between positive and negatively charged particles.  Metallic bonding shares electrons among the ions in a similar manner to how electrons are shared in covalent bonding.  Covalent bonding shares electrons rather than having electrostatic charges.  Ionic bonding will form compounds whereas covalent bonding can form a compound or element and metallic bonding is strictly found in elements

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