Material Technology

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Material Technology
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Objectives

1. Explain that technological problems require a
   multidisciplinary approach. (ITEA, STL 10-L)
2. Select and use tools and instruments in the
   testing and evaluation of design solutions.
3. Evaluate final solutions and communicate
   observations, processes, and results of the
   entire design process, using verbal, graphic,
   quantitative, virtual, and written means, in
   addition to three-dimensional models. (ITEA, STL
   11-R)
4. Identify and describe applications of materials
   technology in the designed world such as metals,
   alloys, nonmetals, composites, and biomaterials.
5. Explain science concepts and mathematical
   concepts applied in materials technology such as
   strength of shapes, forces, center of gravity,
   moments of inertia, stress, strain, deflection,
   and efficiency.

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The Big Idea
Engineering, the systematic application of
mathematical, scientific, and technical
principles, produces tangible end products that
meet our needs and desires.
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Purpose of Lesson
To familiarize students with the functioning and
applications of materials technology by having
them analyze materials in terms of their common
components, basic system design, safety
considerations, and simple controls.
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Materials Technology

• The technology of producing, altering, and
  combining materials.
• Example applications producing paper from wood,
  producing aluminum from ore, drilling holes in
  wood, annealing to soften metal, laminating wood.

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Classification of Materials

• Each type of material has its unique scientific,
  mathematical characteristics.
• Each material has different properties in
  strength of shapes, forces, center of gravity,
  moments of inertia, stress, strain, deflection,
  and efficiency.

• Organics
• Metals and Alloys
• Polymers
• Ceramics
• Composites

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Organics

• Organics are or were living organisms
• Composed of mostly Carbon and Hydrogen
• Structure depends on the way cells developed not
  by human manipulation
• Renewable, sustainable
• Infinite variety
• Genetically alterable

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Metals and Alloys

• Metals are pure elements which comprise about
  three-fourths of the periodic table
• Few are used in their pure form because of
• Hardness too hard or too soft
• Cost scarcity of element
• Engineers need certain characteristics that can
  only be accomplished by a blending of basic
  elements
• Metallic materials include alloys, which are
  combinations of metals and other elements

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Metals

• Possess material properties, including
• high strength and toughness
• high electrical conductance
• high thermal conductance
• luster
• Examples
• aluminum - copper - gold - zinc - iron - lead -
  nickel
• silver - thorium - chromium - tin - beryllium

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Alloys

• Consist of materials composed of two or more
  elements, at least one being a metal
• This combination of elements gives the material a
  combination of properties from each element
• Examples
• Steel- iron, carbon and impurity elements such as
  boron copper or silicon
• Brass - copper, zinc
• Stainless Steel - nickel,iron
• Monel - nickel,copper

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Types of Metallics

• Ferrous Metallics - iron and alloys which contain
  at least 50 iron (e.g. wrought iron, cast iron,
  steel, stainless steel)
• Nonferrous Metallics - Metallic elements other
  than iron (e.g. copper, lead, tin, zinc,
  titanium, beryllium, nickel)
• Powdered (Sintered) Metals (ferrous or
  non-ferrous)
• Sometimes called sintered metal. A process of
  producing small (powdered) particles which are
  compacted in a die and then sintered (applying
  heat below the melting point of the main
  component)
• Examples
  
  gears, bearings, carbide tool inserts

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Polymers

• Polymers
• Chain-like molecule made of many (poly) smaller
  molecular units (monomers)
• Chaining (polymerization) is responsible for the
  formation of natural fibers, wood, lignin,
  rubber, skin, bone and the tissues of animals,
  humans and insects

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Plastics

• Human-made polymers
• Plastics are workable or moldable
• Thermosetting plastics are formable once (e.g.
  epoxy, phonelic (Bakelite), polyurethane)
• Thermoplastics can be heated repeatedly and
• formed into new shapes
• (e.g. polyethylene, nylon, Plexiglas)

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Elastomers

• Elastomer
• amorphous (shapeless) structure consisting of
  long coiled-up chains of entangled polymers
• can be stretched at room temperature to at least
  twice its original length and return to its
  original shape after the force has been removed
• Process to strengthen an Elastomers
  vulcanization
• a chemical process used to form strong bonds
  between adjacent polymers to produce a tough,
  strong, hard rubber (automobile tires)

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Ceramics

• Crystalline compounds combining metallic and non
  metallic elements
• The absence of free electrons make ceramics poor
  electrical conductors.
• Because of the strength of the
• bonding, ceramics have high
• melting temperatures

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Ceramics

• Categories
• Clay
• Refractory
• Electrical and Magnetic
• Glasses
• Cermets

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Ceramics

• Clay Products
• Inorganic material which is shaped, dried and
  fired.
• Examples brick, floor and wall tiles, drainage
  tile, roof tile, sewer pipe, chimney flue, china,
  and porcelain.

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Ceramics

• Refractory Materials
• Ceramics designed to provide acceptable
  mechanical or chemical properties while at high
  temperatures.
• Most are based on stable oxides such as carbides,
  nitrides, and borides.
• An example of a refractory is the machinable
  all-silica insulating tiles on the U.S. space
  shuttle

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Ceramics

• Electrical and Magnetic Applications
• Ceramics are used as resistors and heating
  elements for furnaces (silicon carbide)
• Semiconductor properties
• Thermistors- as they heat-up allow current to
  flow.
• Rectifiers- allow current to flow in one
  direction
• Clay based ceramics for high-voltage insulators

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Ceramics

• Glass
• Based on silica with additives that alter the
  structure or reduce the melting point, optimize
  optical properties, thermal stability and
  resistance to thermal shock
• Cermets
• Combinations of metals and ceramics(oxides,
  nitrides, or carbides) bonded together in the
  same way powdered metallurgy parts are made.
• Examples crucibles, jet engine nozzles

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Composites

• Laminar or Layer Composites - alternate layers of
  materials bonded together. (e.g. plywood, safety
  glass, Formica, bimetallic strips)
• Particulate Composites - discrete particles of
  one material surrounded by a matrix of another
  material. (e.g. concrete, asphalt, powdered
  metals and ceramics)
• Fiber-Reinforced Composites - composed of
  continuous or discontinuous fibers embedded in a
  matrix of another material. (e.g. Kevlar, rayon,
  steel reinforced tires, fiberglass,
  graphite-epoxy)

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Extension

• Elements of the engineering-design process can be
  used in short term problem-solving activities
• learn and practice systematic problem
• solving,
• b) develop and apply their creativity and
  ingenuity
• c) make concrete applications of mathematics and
  science skills and concepts.

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Machine and Tool Safety

• You are to review and take the test for the
  following
• General Safety
• Scroll Saw Safety
• Drill Press Safety
• Turn in the receipts that you made a 100 on each
  of the tests

http//www.mrrhineteched.com/Safety20Website/Home
20Safety20Page.htm
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Lab Safety

1. Follow all directions the first time they are
   given.
2. Be courteous in language and actions.
3. Be on time and prepared to participate.
4. Respect other people and their property.
5. Eye protection must be worn while students are
   processing materials.

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Lab Safety

1. Running and playing is not allowed in the
   Technology Lab.
2. Throwing any object in the Technology Lab is not
   allowed.
3. Students will only be able to use tools and
   machines while the Technology Teacher is in the
   Lab.
4. Students should wear clothing that protects their
   arms, legs, and feet from injury.
5. Keep the floor and working surfaces clean and dry
   at all times.

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Lab Safety

• Hair that presents a safety hazard must be tied
  back.
• Respect all tools and machines.
• When in doubt, ask your Teacher.
• Report any incident to the Teacher.
• Avoid the 250 word essay follow the safety
  rules.

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Machine Safety Application Block
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Step 1 Layout Cut Lines
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Step 2 Mark Centers for Holes
X
X
X
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Center Punch Holes
Use mallet and center punch to accurately mark
all centers to be drilled.
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Drill Holes

• Follow all safety rules
• Carefully drill each hole to required size

Set up and drill
Finished example
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Cut out Parts
Select and use the correct machine to cut your
motor base out
The slower you cut, the nicer your parts will be