Die casting is a moulding process in which molten metal is injected under high pressure and velocity into a split mould die. It is also called pressure die casting.
Uniform Wall Thickness
Maintain uniform wall thickness to achieve a minimum porous die casted product.
Depending upon the casting size, the recommended wall thickness is between 0.38 and 6.3 mm.
If wall thickness is not uniform it affects metal flow, resulting in air enclosures and poor surface finish of parts.
Fillet and Radii
Sharp internal corners in die casting are to be avoided.
Radii and fillets should be 1.5 times the wall thickness for both inside and outside radii.
If fillets and radii are not provided it increases stress concentrations in the component and the die
Draft Angle
For the case of the outside wall, the recommended draft angle should be the half of the draft angle used in the inside wall.
The draft angle will depend upon the type of material and varies inversely with height of the wall.
Without draft, parts run the risk of poor cosmetic finishes, and may bend, break, or warp due to molding stresses caused by the plastic cooling.
Mould Wall Thickness
Ribs and bosses which are too close to each other can result in thin mold walls.
The minimum clearance between features of a cast component will be based on the casting process, component material and tool material.
If the mold wall is too thin and elongated, stresses are developed in the mold, reducing mold life.
Ninad Kashid
Aug 24, 2022