sand casting

There are two kinds of molding in sand casting, one is commonly known as green sand casting and the other is known as air set sand castings. Both methods work by packing the mixture around a master patter for forming the mold cavity, the pattern is removed from the cavity and the final mold is formed by two parts generally called the cope and drag. The molten aluminum is poured then into de mold, when its time the sand mold is destroyed, obtaining like this the aluminum product in its first phase.

via aluminum foundry's blog