What is Our Engineering Research Project?

Vinay Dulip Chemistry Teacher – Moody High SchoolMarguerita Guerra Science Specialist – MacArthur High School

Synthesis of bulk nanocrystalline

metals by severe plastic deformation

E3 Teacher Summer Research Programfor Secondary Math and Science Teachers

Teacher Preparations

• Lesson taught as nature of science lesson• Prebake clay pieces at 3 minute intervals the day before• Complete questions as introduction• Complete bending exercise as part of introduction

Hardness

• The ability to resist being scratched.• Object made of hard material will scratch

material made of softer material.

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Free?

Think about it!• How many of you own CDs?• What is the most common damage to your CDs?• What happens when you place your iPod or cell

phone in your pocket or purse and your coins or keys come in contact with your iPod?

What is the definition of hardness?

Hummer H2 Sport Utility Truck• Made with about seven pounds of nanocomposite material, the cargo

bed Hummer's H2 SUT is lighter and more scratch proof than older plastics. Besides the weight advantage, GM says the nanocomposite parts don't change shape when exposed to temperature changes.

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Scratch ..

• “I got me one of them shiny new black iPods a couple weeks back. It’s real purty. While the black is very nice looking, it’s also going to scratch if you breath on it with anything less than freshly brushed teeth.”

• Made from highly scratch-resistant materials such as hard metal, high-tech ceramics, sapphire crystal, high-tech lanthanum and high-tech diamonds, these watches are destined to last a lifetime.

• Thanks to a choice of sturdy, scratch-resistant materials and no-nonsense design, the T60 absolutely reeks of quality. I’d use one to stop a bullet, if I had to.

• Scratch Resistance Hard Coat is a layer material that is harder than the base material. The hard coat material is chemically bonded to the base material and its degree of hardness will depend on the flexibility of the base lens material.

ObjectiveThe student will experimentally determine the relationship between hardness and temperature by indenting various pieces of clay that have been heated for various time periods.

Materials

• Indenter

• Metric ruler • 6 pieces of clay heat treated for different time

periods • Graph paper

Procedure for Clay Indentations

• Safety Reminder: Test the hardness of clay pieces only.

• Place Clay A on the indenter device.• Lift the arm of the indenter 900.• Drop the indenter arm on the clay.• Measure the depth of the indentation.• Repeat above steps with Clay B, Clay C, Clay D, Clay

E, Clay F and Clay G.

Procedure for Metal Indentations

• Place the metal on the indenter device.• Lift the arm of the indenter 900.• Drop the indenter arm on the clay.• Repeat steps 1-3 with the other metal.

Fancy Oven for heat treatment (Annealing)

Indents in Control and longest timed sample

Control Sample not bakedSample baked for

18 minutes

Construct a table with the data collected.

Polymer Clay A B C D E

Depth in mm - Trial 1

Depth in mm - Trial 2

Average depth –(Indent)

Construct a graph illustrating the relationship between the depth of the indentation vs. the amount of time the clay was heated.

Depth in mm vs. Time in Minutes for Polymer Clay

0

5

10

15

20

0 5 10 15 20

Time in Minutes

Dep

th i

n m

m

Best Fit - Exponential

Depth in mm vs. Time in Minutes for Polymer Clay

-5

0

5

10

15

20

0 5 10 15 20

Time in Minutes

Dep

th i

n m

m

Best Fit - Linear

Conclusion• Is the force applied to the clay pieces varied or held

constant? Explain• What is the independent variable in this experiment?

Why?• What is the dependent variable in this experiment?

Why?• What is the control in this experiment?• What is the relationship between the depth of the

indentation and the amount of time the clay was heated?

• Based on your data and observations, describe what happens to the hardness of the clay as it is heated.

Acknowledgements

Special thanks to • Dr. X. Zhang • Engang Fu• Nan Li• Dr. Shrinivasa• Dr. Conkey

The experience was what it was because of each of you!

Have a Whale of A Day!