 Once the molds are split, the metal plate must be removed from the
mold with the mold intact. This is so the depths of the thermocouples can be
measured. In this photo and the one below, Jon is using the handheld reciprocating
saw to cut through the runners which fed the casting. |
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Closeup view of Jon cutting the runners in order to remove the plate. After these
are severed, the plate will be taken out of the mold cavity. |
| After
the runners are cut, the plate is still held into the mold cavity due to the vents.
These are necessary during the cast to allow air to escape from the cavity. Molten
metal which partially filled the vents during the cast are now solid, and hold onto the
mold like fingers. In this photo, Jon and Quanpeng are knocking the plate out of the
mold. |
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After
the plate is finally removed from the mold, the thermocouples must be located by carefully
removing sand in the area where they were installed. After they are located, a depth
micrometer (at left, and detail below) is used to determine the actual
thermocouple location relative to the mold surface. |
| The
depth micrometer is placed over the now-exposed thermocouple. Five readings (with
the base of the micrometer rotated each time) are obtained to get an average depth. |
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Next
we weigh the mold and the flask. This allows us to calculate the bulk density of the
sand in the mold. The weight of the sand must be determined also in order to attain
the proper moisture content when the sand is recylcled. |
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Finally, the molds can be broken. Here Chris is using the sledge to break the mold
over a wheelbarrow. Obviously, the instrumentation from the previous test must be
removed from the sand before it can be recycled. |
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The
sand is placed in this large mixer, called a muller. This muller can mix about 60kg of
sand at a time. After determining the initial moisture content of the reclaimed
sand, an appropriate amount is added to bring the moisture content to the desired level
for the next mold. |
