Sand casting is a common and simple way to produce metal parts.
- Pattern
- Draft Angle
- Types of patterns
- Match Plate
- Mold
- Sand
- Binders
- Cores
- Sand
- Binders
- Sodium Silicate
- Phenolic Urethane Cold Box Process (PUCB)
- See: Shell Molding
- Sand casting is the most common and versatile form of casting
- Granular material is mixed with clay and water
- Packed around a pattern
- Gravity flow is the most common method of inserting the liquid metal into the mold
- Metal is allowed to solidify and then the mold is removed
![](http://toolnotes.com/wp-content/uploads/2021/02/CastingTerminology-1024x497.png)
![](http://toolnotes.com/wp-content/uploads/2021/02/Draft-1024x709.png)
Process
The process begins with a pattern. Patterns should be:
- Made of a stable material
- Oversized to accommodate shrinkage
- Include draft angles
- Include generous fillets and rounds (avoid sharp corners)
Here, a split pattern is used. The two halves of the split pattern nest together.
![](http://toolnotes.com/wp-content/uploads/2021/02/SandCasting1-1.png)
The pattern is covered with parting compound and sand is rammed into the flask to form the drag. Excess sand is removed by a process known as strickling.
![](http://toolnotes.com/wp-content/uploads/2021/02/SandCasting2-1.png)
![](http://toolnotes.com/wp-content/uploads/2021/02/SandCasting3-1.png)
When the drag has been rammed and strickled, it is inverted and the cope half of the pattern is placed.
![](http://toolnotes.com/wp-content/uploads/2021/02/SandCasting4-1024x741.png)
Parting compound is added on top of the cope half of the pattern and the cope is rammed with sand.
With the cope rammed, sprue and risers are cut.
![](http://toolnotes.com/wp-content/uploads/2021/02/SandCasting5.png)
The mold is then disassembled and runners are cut from the sprue and riser. If cores are used, they are inserted into the core prints at this time.
![](http://toolnotes.com/wp-content/uploads/2021/02/SandCasting6-1024x716.png)
The mold is then re-assembled and is ready to be poured.
![](http://toolnotes.com/wp-content/uploads/2021/02/SandCasting7.png)
The mold is poured and allowed to cool.
![](http://toolnotes.com/wp-content/uploads/2021/02/SandCasting8.png)
When the part has cooled it is removed from the sand.
![](http://toolnotes.com/wp-content/uploads/2021/02/Rough-Cast-Part.png)
Gates and runners must then be removed. This process is known as fettling.
![](http://toolnotes.com/wp-content/uploads/2021/02/SandCasting10-1024x549.png)
References
“Innovative Latest Technology and Measurement Systems of Refractory Coatings. Chandan Panda, Forace Polymers Pvt. Ltd. https://www.foundry-planet.com/fileadmin/redakteur/pdf-dateien/25-Chandan-Panda.pdf Accessed 16 Mar. 2021.
“Phenolic Urethane No Bake Process.” HA-International, https://www.ha-international.com/content/products/resins/nobake.aspx. Accessed 16 Mar. 2021.
“StackPath.” StackPath, https://www.foundrymag.com/molds-cores/media-gallery/21153249/phenolic-urethane-cold-box-environmental-advantages-ha-international. Accessed 16 Mar. 2021.
Recent Comments