Indicator Statement

Analyze the functioning and applications of materials technology.

 

Objective(s):

Identify and describe applications of materials technology in the designed world. Such as:

Metals

Alloys

Nonmetals

Composites

Biomaterials

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

Efficiency

• Throughout history, people have used materials to design and create the tools, machines, shelters and other items that solves problems and extends our capabilities.

Engagement

Engagement

•Take a moment and look at what you are wearing today.•How many different materials can you identify?

Rubber, Nylon, Leather, Cotton, Polyurethane

Cotton, Polyester, or a Cotton/Polyester blend

Cotton, Metal

• Materials are all around us.

• We use all types of materials for all types of reasons.

• You will have 5 minutes to identify as many different types of materials found in the classroom as possible

• List the item and what you think it is made of.

Exploration

Exploration

•How many did we find?•Are different items made with the same materials?•Are the same items made with different materials?

Explanation

• 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.

Explanation

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

• 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.

Explanation

• 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

Explanation

• 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

Explanation

• 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

Explanation

• 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

Explanation

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

Explanation

• 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

Explanation

– 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)

Explanation

• 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)

Explanation

• 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

Explanation

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.

Explanation

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

Explanation

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

Explanation

• 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)

Explanation

•Biomaterials can be made from natural or synthesized in the lab.•They are often used and/or adapted for a medical application, and comprises whole or part of a living structure or biomedical device•The Biomaterial will perform, or replaces a natural function.

•Examples of this are artificial knees, Heart Valves and Dental Implants

• You will create a page for your ePortfolio that describes all of the major types of materials.– Metals– Alloys – Nonmetals– Composites– Biomaterials

• Describe the properties and characteristics of the material

• Describe a test that can be done to determine the type of material

• Explain were the material can be used• Include a picture

Elaboration

• Students assess their knowledge, skills and abilities.

• Activities permit evaluation of student development and lesson effectiveness.

Evaluation