Introduction: Green Sand Casting With Aluminum
This is the casting of aluminum parts with green sand.
Step 1: Prepare the Sand
In preparation for the sand casting lab, the sand,
clay, and water were combined and mixed. 50Lbs of #180 grain sand, 50lbs of #120 grain sand, 7lbs of clay, and 1 qt. of water were combined in the muller. The muller coats the sand with clay and adds enough moisture to allow the sand mixture to stick together enough to hold its form.
1. Add the sand to the muller.
2. Add water a little at a time before adding clay.
3. Continue mixing as you slowly add clay.
4. Add additional water if needed to obtain desired texture.
Step 2: Fill the Pattern With Sand
The coupler mold consists of the flask (cope and drag),
pattern and a core box.
1. Starting with the drag, place the female half of the coupler pattern into the center on a bottom board.
2. Add a light dusting of parting dust (eg. baby powder).
3. Add sand mixture a little at a time while pressing
it down and around the pattern. The sand takes the form of the contours of the pattern.
4. Fill the drag and compress the sand until it reaches the top.
5. Scrape off the sand above the rim of the drag.
6. Flip the drag and place the cope on top of it. Add
the male half of the pattern onto the female half.
7. Place the tube for the sprue upright adjacent to the pattern and the vent/riser directly on top of the pattern.
8. Add sand and pack it around the pattern, sprue, and vent. Pack sand up to the rim of the cope.
9. remove the tubes for the sprue and vent/riser.
10. Separate the cope and drag. Remove the patters from both.
11. Press a runner from the sprue to the mold cavity.
Step 3: Create the Core Mold
The core box will allow you to create 2 sand molds for the core.
1. Add a little parting dust to the core box.
2. Add a little sand to the core box and press down.
3. Place metal wires onto the sand in the core box to add structural integrity to the core.
4. Fill core box to top and press firmly. Scrape sand level with the box.
5. Place core box upside-down onto 2 strips of paper. Gently tap the box to release the sand core onto the paper strips.
6. Repeat steps 1 through 5 for the second half of the core.
7. Use the paper strips to lift and place the core into the mold cavity one half at a time.
8. Replace the cope to the drag and press sand onto the pins to keep metal from forming to them.
9. Cut a pouring cup onto the top of the sprue.
Step 4: Pour the Aluminum and Cooling
Pouring the molten aluminum is done at roughly 1350°F – 1450°F. Its melting temperature is 1220°F.
1. Bring the flask to the sand pit.
2. Use pick-up tongs to remove the clay graphite crucible from the Stationary crucible furnace.
3. Use pouring shank to pour the liquid aluminum into the pouring cup.
4. Pour excess aluminum into an ingot mold.
5. Allow the casting to cool for 15 minutes.
6. Break away the sand from the casting.