If you're reading this, chances are you heard the term 'green sand casting' and 'foundry' in the same conversation. Simply put, green sand casting is a process used by foundries all over the world to produce ferrous and nonferrous castings. Green sand today is the most popular process in North America to produce castings.
Think of your footprint on a sandy beach slowly filling up with water...in theory producing a green sand casting is not much different, albeit a bit more work. Instead of sand found on the beach, foundries use their own blend of silica sand, bentonite clay, and water to develop what is known as 'green sand' (which is actually black in color....'green' refers to the moisture in the sand). This combination of ingredients is used because it can withstand the extremely high temperatures of liquid metal.
Once the sand is refined, impressions are then formed (much like how you would step into beach sand to create a footprint). Liquid metal is poured to fill the hollow shape and solidifies into a casting. After about an hour of cooling (depending on the alloy), the used green sand is broken away and recycled. What remains is a solid casting. When volumes tend to get high, this entire process can be automated.
That's green sand casting in a nutshell!
Comments