SECOND EXAM
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SECOND EXAM Fall 2008. pages of the exam- Bond, James ening” of aluminum alloys. Detail both microstructure and mechanical s. ench – Supersaturated solid solution , age – +GP zones – under aged - weak mum strength, + ’ – overaged -weaker. NO MARTENSITE. Hardness v time curve slocation and what is a screw dislocation. Show how a Burgers circuit nd compare Burgers vectors for an edge and screw dislocation. slocation line parallel to motion, screw – b is parallet to line 90 to motio <111> BCC, (0001)<1120> HCP, Shear stress moves them above elastic limit. nsite is formed. What is a TTT and a CCC curve? How does alloying lter these curves? ite so quench from above 727C to below Ms. TTT – time transformation curve, ing curve, Cr and Ni increase hardenability, moves curves to longer t d steel”? How do you get a spherodized structure in a steel? rmed by heating a MARTENSITIC steel below eutectoid to form very small carbi properties. Spherodized – PEARLITCIC steel heated just below eutectoid to produce large spheres of carbide – 650C for 24 hours.
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SECOND EXAM. CHE 333 Second Exam – Fall 2008. Put your name on all pages of the exam- Bond, James Describe “Age Hardening” of aluminum alloys. Detail both microstructure and mechanical property changes. - PowerPoint PPT Presentation
Transcript of SECOND EXAM
SECOND EXAMCHE 333 Second Exam – Fall 2008.Put your name on all pages of the exam- Bond, James1. Describe “Age Hardening” of aluminum alloys. Detail both microstructure and mechanical property changes.Solution treat –, quench – Supersaturated solid solution , age – +GP zones – under aged - weak, + ” peak aged optimum strength, + ’ – overaged -weaker. NO MARTENSITE. Hardness v time curve2. What is an edge dislocation and what is a screw dislocation. Show how a Burgers circuit is constructed and compare Burgers vectors for an edge and screw dislocation.Edge - b is 90 to dislocation line parallel to motion, screw – b is parallet to line 90 to motion, slip planes{111}<110> FCC, {110}<111> BCC, (0001)<1120> HCP, Shear stress moves them above elastic limit.3. Describe how martensite is formed. What is a TTT and a CCC curve? How does alloying with Cr and Ni alter these curves?Only to BCT martensite so quench from above 727C to below Ms. TTT – time transformation curve,CCC – continuous cooling curve, Cr and Niincrease hardenability, moves curves to longer times.4. What is a “tempered steel”? How do you get a spherodized structure in a steel? Tempered steel formed by heating a MARTENSITIC steel below eutectoid to form very small carbidesto control mechanical properties. Spherodized – PEARLITCIC steel heated just below eutectoidfor long time periods to produce large spheres of carbide – 650C for 24 hours.
CHE 333 Class 17Materials for Vampires
“To nibble or not to nibble, that is the question” – Willy Shakespeare
LOCATION, LOCATION
Top left – Whitby Abbey where Dracula landed inEngland. Bottom left and above – Robin HoodsBay toward Ravenscar and alleys, inspiration forBram Stoker writing Dracula.
MATERIALS FOR STOPPING DRACULA
Wood – legendary choice – stake to the
heart only solution that works.
Other materials – garlic round neck – early
bio-tech?
Lightweight materials.
Wood Properties
CHOOSE KILN DRIED HICKORY PECAN AS STRONGEST?
Wood Structure
Carbon Composite Properties
Handle of light weight carbon fiber composite?
Carbon Fiber Composite Structure
Testing Adhesive Bonds
Composite
Adhesive
Conversion Coating
Metal
Load to failure
Lap shear testing conducted. Samples arestressed to failure and the failure stressrecorded.
Adhesive Bonding Degradation
0
1000
2000
3000
4000
5000
6000
7000
0 1 2 3 4 5 6
Number of Weeks
conventional treatmentperoxide-titanate treatmentfit (conventional treatment)fit (peroxide-titanate treatment)
Effect of marine exposure to joint strength for a carbon fiber composite to titanium bondRemember the human body fluids are salt containing.
Metal Matrix Composites
Similar structure to carbon fiber composites and similar joining problemsContinuous fibers – long: discontinuous - chopped strandsParticulate – non thermodynamic phase, added to meltCarbon fiber composites are stronger.
Coatings
Handle needs some grip!!
Spray on coatings.
Paints – polymers such as latex, with a
particle such as sand for friction.
A LIGHTER FASTER DRACULA
CLOTHING
Mandatory Cape, black suit, white shirt and waistcoat – clothing, usepolypropylene coated films, like chippackaging?
Need to fly and be undetected so nonmagnetic materials, ie no ferritic steels.
Protection from stake important. Light Armor Plate. Aluminum Alloy
2219?Kevlar and carbon fibers easily cut!!
Specific Properties Compared
Specific properties are normalized with density, so weight is taken into account for the same volume.
Teeth - for a little nibbling
Teeth – calcium based, not that strong.
Ceramic better?
DRINKING UTENSIL
Traditional Glass.
Disadvantages• Brittle – fractures every time thrown into
empty fireplace.• Difficult to decorate “fashionably”• Dishwasher safe?
Plastic Container.
Advantages.• Ductile - absorbs impacts without failure when thrown.• Can decorate easily by adhesive bonding so Dracula can show home crafting skills. ( Sell on Internet – business opp?)• Light weight.• Many colors and shapes available.
PROTECTION OF POTENTIALVICTIMS
BITE PROTECTION• Location known – neck region.• Hard Materials – overlapping double layer of
ceramic plates, designed so joint in top layer covered by lower layer. Thickness, ie, teeth cannot get through material – reinforced composite 12.5mm thick to wear around neck.
• Lightweight.• Coat decoratively with gold or a few diamonds
Conclusions
Modern Materials would help both sides!!!
Happy Halloween!!!.
