Get the box of Stuff Wood, steel, aluminum, melamine

Get the box of StuffGet the box of StuffWood, steel, aluminum, melamine Wood, steel, aluminum, melamine

Properties of Properties of MaterialsMaterials

Goal: Students will be able to Goal: Students will be able to describe various physical describe various physical

properties that materials haveproperties that materials have

DiscussionDiscussion

differentiate between chemical and differentiate between chemical and physical propertiesphysical properties

At your tables list examples of chemical At your tables list examples of chemical and physical properties.and physical properties.

I will call on each table and make a list I will call on each table and make a list of all the ones we can think of. of all the ones we can think of.

Chemical PropertiesChemical Properties

how a material interacts with another how a material interacts with another materialmaterial

““social” behaviorsocial” behavior

response to other matter (or lack of response to other matter (or lack of response)response)

reactionsreactions

Chemical PropertiesChemical Properties

Examples:Examples: burningburning reaction with acidreaction with acid reaction with waterreaction with water corrosion/rusting/oxidationcorrosion/rusting/oxidation others????others????

Physical PropertiesPhysical Properties

characteristics it possesses by itself characteristics it possesses by itself (in and of itself)(in and of itself)

““personal” traitspersonal” traits

response to energyresponse to energy

Physical PropertiesPhysical Properties

colorcolor sizesize texturetexture melting pointmelting point boiling pointboiling point solubilitysolubility

lusterluster densitydensity magnetismmagnetism odorodor viscosityviscosity crystalline crystalline

structurestructure

Physical PropertiesPhysical Properties Electrical Electrical propertiesproperties

conductor or insulatorconductor or insulator

Optical Optical properties – response to lightproperties – response to light index of index of refraction refraction – bending of light– bending of light transparenttransparent – light passes through – light passes through translucenttranslucent – some light passes through but – some light passes through but

no distinct imageno distinct image opaqueopaque – no light passes through – no light passes through

Physical PropertiesPhysical Properties

ThermalThermal properties – response to properties – response to heatheat

conductivityconductivity

specific heat – how much energy it takes specific heat – how much energy it takes to change temperatureto change temperature

thermal expansion – thermal expansion – example: iron wire example: iron wire demodemo

Mechanical PropertiesMechanical Properties

subgroup of physicalsubgroup of physical

response to force or stressresponse to force or stress forceforce – a push or pull – a push or pull

stressstress – force causing a deformation or – force causing a deformation or distortion (force per unit area)distortion (force per unit area)

Mechanical PropertiesMechanical PropertiesExamplesExamples

workabilityworkability malleabilitymalleability – can be flattened – can be flattened ductilityductility – can be drawn into wire – can be drawn into wire

(stretched), bent, or extruded(stretched), bent, or extruded

Mechanical PropertiesMechanical PropertiesExamplesExamples

brittlenessbrittleness breaks instead of deforming when stress breaks instead of deforming when stress

is appliedis applied

hardnesshardness resistance to denting or scratchingresistance to denting or scratching

Mechanical PropertiesMechanical PropertiesExamplesExamples

elasticityelasticity ability to return to original shape after ability to return to original shape after

being deformed by stress being deformed by stress rubber ball or piece of elasticrubber ball or piece of elastic

plasticityplasticity retains new shape after being deformed retains new shape after being deformed

by stress by stress wet clay ball or piece of saran wrapwet clay ball or piece of saran wrap

Some of the propertiesSome of the properties

At your tables you will find some At your tables you will find some signs with different physical signs with different physical properties. properties.

Go around between tables and Go around between tables and answer the questions on a separate answer the questions on a separate piece of paper.piece of paper.

Index of RefractionQuestion. What two materials here have a similar index of refraction?

(the three materials are glass, HDPE, and mineral oil)

Electrical conductivityWhat materials here are non-conductive electrically?

(the materials are brass, copper coated steel, wax, glass and carbon fiber)

HardnessWhich material here is the hardest?

(Pine and Melamine)

Mechanical PropertiesMechanical PropertiesExamplesExamples

toughnesstoughness ability to absorb energy ability to absorb energy resistance to fractureresistance to fracture

strengthstrength resistance to distortion by stress or resistance to distortion by stress or

forceforce several types: tensile, compressive, several types: tensile, compressive,

torsional, bending, sheartorsional, bending, shear

Types of Types of Stresses/ForcesStresses/Forces

TensionTension pullingpulling examples:examples: tug-of-war, slingshottug-of-war, slingshot

CompressionCompression pushing together or squeezingpushing together or squeezing examples:examples: bed springs, can crusher, bench visebed springs, can crusher, bench vise

stress

strain

Ceramic orglass

metal

polymer

straight line = elastic regioncurved line = plastic region

City of MaterialsCity of Materials

http://www.cityofmaterials.com

General Classes of General Classes of MaterialsMaterials

PolymersPolymers

CeramicsCeramics

CompositesComposites

Metals and AlloysMetals and Alloys

Metals and AlloysMetals and Alloys

Wood and Wood Wood and Wood ProductsProducts

Free writeFree write

On a piece of paper please describe On a piece of paper please describe various physical and chemical various physical and chemical properties that material's have. If properties that material's have. If you can include how you could test you can include how you could test those physical properties. those physical properties.