Properties of Properties of MaterialsMaterials

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differentiate between chemical and differentiate between chemical and physical propertiesphysical properties

list examples of eachlist examples of each

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

http://www.youtube.com/watch?v=i1x-vJ85sBAhttp://www.youtube.com/watch?v=i1x-vJ85sBA

http://www.youtube.com/watch?v=eF5943tlbBshttp://www.youtube.com/watch?v=eF5943tlbBs

Mechanical PropertiesMechanical PropertiesExamplesExamples

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

deformed by stress deformed by stress rubber ball or piece of elasticrubber ball or piece of elastic http://www.flixxy.com/golf-ball-slow-motion.htm

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

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

Mechanical PropertiesMechanical PropertiesExamplesExamples

toughnesstoughness ability to absorb energy ability to absorb energy resistance to fractureresistance to fracture http://www.steeluniversity.org/content/html/eng/charpy-test.asphttp://www.steeluniversity.org/content/html/eng/charpy-test.asp http://www.youtube.com/watch?v=a_aOlh6dSA8http://www.youtube.com/watch?v=a_aOlh6dSA8 http://www.youtube.com/watch?v=N276_xjl04g&feature=related http://www.youtube.com/watch?v=N276_xjl04g&feature=related

strengthstrength resistance to distortion by stress or forceresistance to distortion by stress or force several types: tensile, compressive, torsional, several types: tensile, compressive, torsional,

bending, shearbending, 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

Types of Types of Stresses/ForcesStresses/Forces

TorsionTorsion twistingtwisting example: wringing out a wet towelexample: wringing out a wet towel

ShearShear opposite forces not lined upopposite forces not lined up examples: scissors, pin in a wagon tongue, examples: scissors, pin in a wagon tongue,

shear pinshear pin

Stress-Strain CurveStress-Strain Curve

StressStress cause cause force causing a deformation or distortionforce causing a deformation or distortion

Strain Strain effecteffect change caused by stress (ex. change caused by stress (ex.

elongation)elongation)

stress

strain

Ceramic orglass

metal

polymer

straight line = elastic regioncurved line = plastic region

City of MaterialsCity of Materials

http://dev.sancsoft.com/http://dev.sancsoft.com/educationasm/asmeducation.html educationasm/asmeducation.html

http://www.cityofmaterials.comhttp://www.cityofmaterials.com

Tensile testsTensile tests

http://www.youtube.com/watch?v=SzJ4YLbMF-Y&NR=1http://www.youtube.com/watch?v=SzJ4YLbMF-Y&NR=1 http://www.youtube.com/watch?http://www.youtube.com/watch?

v=W5A8gU37wGg&feature=relatedv=W5A8gU37wGg&feature=related Close up of tensile strain and break Close up of tensile strain and break

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

DensityDensity

DensityDensity

how much “stuff” per how much how much “stuff” per how much “space”“space” stuff = matter (mass)stuff = matter (mass) space = volumespace = volume per = divideper = divide

Density = Density =

Unit = g/cmUnit = g/cm3 3 or g/mL or g/mL

massmass

volumevolume

MassMass amount of matteramount of matter measured with a balancemeasured with a balance unit = grams (g)unit = grams (g)

MassMass

VolumeVolume

Volume Volume how much space it occupieshow much space it occupies liquidsliquids

measured with a graduated cylindermeasured with a graduated cylinder unit = mLunit = mL

solidssolids regular-shapedregular-shaped

find the dimensions and use an equationfind the dimensions and use an equation irregular-shapedirregular-shaped

use the water displacement methoduse the water displacement method units = cmunits = cm33

1cm1cm33 = 1 mL = 1 mL

Variations in DensityVariations in Density

Density varies with change in temperature Density varies with change in temperature of a substance.of a substance. warmer is usually less densewarmer is usually less dense warm objects/substances usually expandwarm objects/substances usually expand same mass, more volumesame mass, more volume

Density does Density does notnot vary with a change in vary with a change in amount of a substanceamount of a substance Which is more dense:Which is more dense:

a gram of aluminum or a kilogram of aluminum?a gram of aluminum or a kilogram of aluminum?

Calculating Density of an Calculating Density of an Unknown SolidUnknown Solid

Procedure:Procedure:

You must do two cylinders, two cubes, and You must do two cylinders, two cubes, and one irregular shaped solid.one irregular shaped solid.

Make a table to record all data.Make a table to record all data.

1. Record the identifying letter of the sample.1. Record the identifying letter of the sample.

2. Measure and record the mass.2. Measure and record the mass. Use the entire sample for the irregular shaped Use the entire sample for the irregular shaped

solid.solid.

Calculating Density of an Unknown Calculating Density of an Unknown SolidSolid

3. Measure and record the dimensions of the 3. Measure and record the dimensions of the regular shaped solids.regular shaped solids.

Use the digital calipers and convert mm to cm Use the digital calipers and convert mm to cm (move decimal point one place to the left). (move decimal point one place to the left).

cube: length, width, and heightcube: length, width, and height cylinder: diameter and heightcylinder: diameter and height

4. Use water displacement to find the 4. Use water displacement to find the volume of the irregular shaped solidvolume of the irregular shaped solid

Record it in your data table.Record it in your data table. Use the entire sample.Use the entire sample. Describe the basic procedure for water Describe the basic procedure for water

displacement in your journal.displacement in your journal.

Calculating Density of an Unknown Calculating Density of an Unknown SolidSolid

5. Calculate and record the volume for 5. Calculate and record the volume for the regular shaped solids using the the regular shaped solids using the following formulas:following formulas:

cube: volume = length x width x heightcube: volume = length x width x height

cylinder: volume = πrcylinder: volume = πr22hh radius = diameter/2radius = diameter/2 π = 3.14π = 3.14

Calculating Density of an Unknown Calculating Density of an Unknown SolidSolid

6. Calculate and record the density of 6. Calculate and record the density of the five materials.the five materials. Be sure to include units.Be sure to include units. Record the formula for density in your Record the formula for density in your

journal.journal.

7. Use the list of densities to identify 7. Use the list of densities to identify each material and record your each material and record your choice.choice.