Features:

Some of the quality of permanent mould is given below:

• The mould is utilized repeatedly and is designed such that it can be separated to eject and remove the casting.
• The  material  to  be  cast  is  poured  into  the  mould  cavity  under  normal gravitational force.
• Metallic moulds facilitate quicker cooling rates unlike sand mould.
• Due to faster cooling rates grain refinement and elimination of porosity with a consequent go up in room temperature strength occur.
• Usually  Castings  produced  by  this  procedure  contain  a  higher  degree  of dimensional accuracy than castings generated in sand moulds. This is because of higher stability of metallic moulds.
• This procedure is characterized by high cost of tooling. So, this is costly for low production quantities.
• This is difficult to cast material through this procedure where there is problem in locating parting surface and eliminating the casting from mould is not simple.
• Shapes having undercuts are complicated to cast through this procedure.
• Special coatings are needed to protect the mould from attack by molten metal and to reduce thermal shock to the moulds.
• Any modification in the design of the part or in the gate or riser system of a permanent mould is much more costly and difficult to adapt than in sand molding process.
• Permanent mould casting allows the production of more consistent castings with superior surface finish and improved mechanical properties.
• Metals that may be cast in permanent moulds along with Al, Mg, Zn and Cu alloys and hypereutectic gray iron etc.

The major applications of permanent mould casting are in developing of automobile pistons, cylindrical blocks, connecting rods, stators and aircraft fittings.