Fluidity refers to the ability of liquid alloy to fill the mold.
The fluidity of the alloy liquid is good, and it is easy to fill the cavity to obtain castings with clear contours and complete dimensions. On the contrary, if the fluidity of the alloy is not good, defects such as insufficient pouring, cold barrier, pores and slag inclusion are easy to occur.
Among the commonly used alloys, gray cast iron and silicon brass have the best fluidity, and cast steel has the worst fluidity.
There are many factors that affect fluidity, among which are the chemical composition of the alloy, the pouring temperature and the filling conditions of the mold.