How many kinds of casting types of Fused zirconia corundum ?
PT
Shrinkage voids are located under the casting scar.
QX
Shrinkage voids are located at one side of the casting face, while a dense texture is formed in the other side.
WS
Shrinkage void free.
ZWS
A small number of voids remain at the sawn face, ZWS is similar in appearance to WS.