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ENGINEERING 232 - Engineering of Materials

Go to Semester: Spring 2001, Spring 2002, Spring 2003, Spring 2004, Spring 2006

Analytical electron microscopes are used to teach principles of high-precision engineering design and microcharacterization of materials.

Scanning electron microscopy (SEM) of materials.
Below are SEM micrographs of the broken ends of a brass (left) and a copper (right) slug. The slugs were prepared from a lab session demonstrating mechanical properties of materials using the Instron to stretch the slugs to the breaking point. The SEM reveals that the two materials have different microstructure that, in part, accounts for their different behavior under strain.

ENGR232_SEM8_Brass_15kV_Spot3.jpg (92685 bytes) ENGR232_SEM10_Copper_15kV_Spot3.jpg (63371 bytes)

Interpretation of data from scanning electron microscopy (SEM).
Below are two SEM micrographs of the same integrated circuit (IC) that demonstrate the importance of understanding the instrument's operating parameters. The micrograph on the left was captured using a 5KV electron beam; on the right, a 15KV beam. The surface of the material exhibits different characteristics depending on the energy of the incoming radiation used to display them. These differences may be quantitated to yield meaningful data about the IC components.

ENGR232_SEM2_IC_5kV.jpg (48243 bytes) ENGR232_SEM3_IC_15kV.jpg (55161 bytes)

Transmission electron microscopy (TEM) and X-ray energy dispersive spectroscopy (EDS).
This an EDS spectrum from a 500um region of stainless steel, as visualized in the transmission electron microscope, that demonstrates the presence of iron (Fe), nickel (Ni), and chromium (Cr).

StainlessSteel.gif (7142 bytes)