Tuesday, June 7, 2011

Overview


Project A- Tensile Material Testing

Mission : To explore the concept of the strength of different materials and the judging scale named young calculus.

Objectives:
•To understand different mechanical properties if materials

•To observe how the three types of materials behave in their mechanical properties under the tensile and bend test

•To understand the major factors that determines those mechanical properties.


Brief information: Tensile Material Testing is used for testing the strength of a material, based on how much it can be stretched before breaking. The material's respective micro-structure will determine how much force it can withstand before snapping.

Project B- Scanning Electron Microscope
Mission: To learn about electron microscopy and develop a better understanding of EDX
procedures and its applications.

Objectives:
-Understand the concept of the electron microscope.
-Learn how to operate an electron microscope properly and safely.
-Learn how to use EDX to derive at the chemical structure of substances.

Brief Information: The electron microscope uses beams of powered electrons to magnify a specimen. The electrons are fired down to the specimen and reflected back into a capturing device, producing an image. It is superior to the normal microscope due to the physics of light which the normal microscope uses.

Procedures:

1. Vent the chamber. This is to enable the specimen to be inserted into the chamber.


2. Press evac. This is to remove the air from the chamber as to make it a vacuum, so that the electrons can travel down to the specimen freely without getting disrupted by the air.


3. Set the optimal acceleration voltage, working distance and spot size.

-Acceleration voltage : The voltage which the electrons will be beamed down to the specimen. Too high a voltage will result in the specimen melting and damaging the SEM.

-Working distance : The distance between the specimen and the electron gun. This is usually in millimeters.

- Spot size : The size and width of the electron beam. It is usually in direct proportion to the specimen size.


4. Turn up the filament SLOWLY. A sudden rush in turning up the filament will result in the filament melting. Turning it up too much will also have a similar effect.


5. Start to beam the electron to the specimen. After this you should get a blurry, unfined image.


6. Adjust the focus knobs, brightness, contrast, X and Y magnifications and general magnification until the image is clear and satisfying.


7. Save the image.


8. Set the voltage to 0 and turn off the beam.


Project C- Composite Materials
Mission- To learn about composite materials and their effectiveness and applications.

Objectives:
- Learn how to combine materials into strong and sturdy materials as hard as diamond.
- Pick up concepts on the atomic structures of combined materials.

Brief information: Composite materials are substances derived from two individual materials. Composite materials are manufactured by converting the default materials into liquid state by melting and combining them in liquid shape and allowing it to cool in the desired shape. Although composite materials are usually stronger then their default materials, there are some disadvantages like the cost of it being quite high as many complex materials are required to form the shape and material. Each part has to be manually formed and layered and baked in a vacuum. It is also brittle as the atom bondings may be interfered in the manufacturing process and the strength of the composite material may be random depending on the atomic bondings.





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