Jessica TerBush, 2nd Place - TEM, X-ray Imaging and Surface Probe Techniques

TEM image of the eutectic region of a die-cast specimen of AXJ530 (Mg-5Al-3Ca-0.15Sr) alloy that was crept for 500+ hours at 100 degrees C at a stress of 110 MPa. This image was taken using the Philips CM-12 TEM on Central Campus, using an accelerating voltage of 120 kV. Two phases are present: primary alpha Mg (lighter contrast) and (Mg,Al)2Ca (darker contrast). The image was taken at the edge of the hole in the TEM foil (white contrast). The foil has been tilted almost 50 degrees from the foil normal, and the image was taken near the [11-20] zone axis of the surrounding primary alpha Mg. A magnification of 28000x was used. The image clearly shows the lamellar nature of the eutectic region in this commercial alloy. It's also interesting to see how the 3D information is compressed into a 2D TEM image. This alloy shows improved creep resistance over other Mg alloys (AZ91, AS21, AM50) and some authors believe this is due at least in part to the thermal stability of the eutectic phases.
Jessica TerBush, 2nd Place - TEM, X-ray Imaging and Surface Probe Techniques
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