module 1

• Historically, the development and advancement of societies have been tied to the ability to produce and manipulate materials
• Objective

  • Define Materials Science and Materials Engineering
  • Enumerate the structure of materials
  • Enumerate the properties of materials
  • Explain the importance of studying Materials Science and Engineering
  • Enumerate the major classification of materials
• Humans initially had access to a limited number of natural materials like stone, wood, clay, and skins
• Knowledge acquired over the past 100 years has empowered scientists to fashion the characteristics of materials
• Properties of materials could be altered by heat treatments and the addition of other substances
• Components of Material Structure

  • Subatomic structure
  • Atomic structure
  • Microscopic structure
  • Macroscopic structure
• Sophisticated electronic devices rely on components made from semiconducting materials
• The development of technologies is associated with the accessibility of suitable materials
• Important properties of solid materials

  • Mechanical
  • Electrical
  • Thermal
  • Magnetic
  • Optical
  • Deteriorative
• Important properties of solid materials include mechanical, electrical, thermal, magnetic, optical, and deteriorative properties
• An advancement in the understanding of a material type often precedes technological progression
• Early civilizations have been designated by the level of their materials development (Stone Age, Bronze Age, Iron Age)
• Scientists came to understand the relationships between the structural elements of materials and their properties in recent times
• Over time, techniques were discovered to produce materials with superior properties, leading to the development of pottery and various metals
• Processing is an important component in the science and engineering of materials
• Structure of a Material

  Relates to the arrangement of its internal components
• Materials are deeply seated in our culture and influence various aspects of everyday life such as transportation, housing, clothing, communication, recreation, and food production
• Tens of thousands of different materials have evolved with specialized characteristics to meet the needs of modern society, including metals, plastics, glasses, and fibers
• Property

  A material trait in terms of the kind and magnitude of response to a specific imposed stimulus
• Properties are independent of material shape and size
• Exposure to elevated temperatures or corrosive environments

  May result in significant reductions in mechanical strength
• An applied scientist or engineer will be exposed to a design problem involving materials
• Metals

  • Composed of metallic and often nonmetallic elements, relatively dense, stiff, strong, ductile, good conductors of electricity and heat
• Many times, selecting the right material involves trading one characteristic for another based on several criteria
• Deteriorative properties relate to the chemical reactivity of materials
• The more familiar an engineer or scientist is with materials characteristics, the more proficient they will be in making materials choices
• High strength in a material

  May have limited ductility, requiring a compromise between properties
• Important components in the science and engineering of materials

  • Processing
  • Performance
• Materials problems

  • Transmission Gear
  • The superstructure for a building
  • An oil refinery component
  • Integrated circuit chip
• Ceramics


  • Compounds between metallic and nonmetallic elements, stiff, strong, hard, historically brittle and susceptible to fracture
• Cost consideration in material selection

  What will the finished product cost, including fabrication expenses
• Classification of solid materials

  • Metals
  • Ceramics
  • Polymers
  • Composites
  • Advanced materials
• Optical properties

  • Light radiation
  • Index of refraction
  • Reflectivity
• Advanced materials are utilized in high-technology applications and are typically traditional materials with enhanced properties or newly developed high-performance materials, may include all material types (metals, ceramics, polymers), normally expensive, include semiconductors, biomaterials, and materials of the future like smart materials and nanoengineered materials
• Polymers

  • Include plastic and rubber materials, organic compounds based on carbon, hydrogen, and other nonmetallic elements, have large chainlike molecular structures with a backbone of carbon atoms, common polymers include polyethylene, nylon, poly(vinyl chloride) (PVC), polycarbonate (PC), polystyrene (PS), and silicone rubber, low densities, mechanical characteristics generally dissimilar to metals and ceramics, not as stiff or strong but comparable on a per-mass basis, extremely ductile and pliable, relatively inert chemically and unreactive in many environments, tend to soften or decompose at modest temperatures, low electrical conductivities, nonmagnetic
• Semiconductors have electrical properties intermediate between conductors and insulators, extremely sensitive to the presence
• Composites

  • Composed of two or more individual materials from metals, ceramics, and polymers, designed to achieve a combination of properties not displayed by any single material, incorporate best characteristics of each component material, various types represented by different combinations of metals, ceramics, and polymers, some naturally occurring materials like wood and bone are composites, commonly synthetic composites, examples include fiberglass and carbon fiber-reinforced polymer (CFRP) composites
• Ceramics


  • Relatively stiff and strong, typically very hard, historically exhibited extreme brittleness and highly susceptible to fracture, newer ceramics engineered for improved resistance to fracture, used for cookware, cutlery, and automobile engine parts, insulative to heat and electricity, more resistant to high temperatures and harsh environments than metals and polymers, may be transparent, translucent, or opaque, some exhibit magnetic behaviour
• Technological challenges remain in materials science and engineering despite progress in recent years
• Electrorheological/magnetorheological fluids


  Experience dramatic changes in viscosity upon the application of electric and magnetic fields