2017 | AFC ACCOMPLISHMENTS 138 and lacks the stiffness to maintain its desired shape, giving a loose fit in the quartz mold.This loose fit in the mold allows the melt to flow around the foil, and the lack of structural integrity of the foil can allow portions of the foil to be pushed into the center of the fuel. On the other hand, the 125 µm foil is quite stiff. Due to its stiffness there was some difficulty with mold assembly, but the ability of this foil to retain its shape during casting produced cast pins with only a little infiltration of the foil near the top of the pin. Figure 1 shows a cross section of the middle of the 125 µm foil pin. Notice the foil fully wraps around the fuel with no infiltration. The 25 µm foil had similar handling difficulties to the to the 12 µm foil, leading to fuel alloy flowing around the foil fully encapsulating the zirconium foil in some areas. The behavior of the 50 µm foil more closely resembled that of the 125 µm foil, but still presented some defects. Although the 50 µm foil did not contain the fuel as desirably as the 125 µm foil, it handled easier and provided a more desirable zirconium content in the fuel pin. Based on the above results another set of experiments was performed in which the 25 µm and 50 µm foils were heat treated in an air atmosphere to produce an oxide layer on the foil and to impart additional stiffness.Two samples of each thickness were heat treated, one sample was rolled and Figure 2. Middle section of heat treated 50 µm foil. SEM image (Right) shows minor infiltration and brittle nature of a possible interaction product.