GLOSSARY

Bloom . The extremely thin surface coating that builds up on the die surface once it has produced a number of castings. It has the effect of improving the surface finish of the diecastings produced, without effecting dimensions.

Cold chamber diecasting . A process where metal is ladled into the metal injection system immediately prior to making each shot.

Cold lap . A surface finish effect produced when casting solidification commences before cavity fill. Not usually significantly detrimental to casting strength but can affect subsequent finishing operations.

Creep . The time dependent strain that takes place under constant load

Electrophoretic painting . Now commonly called electropainting a process analogous to electroplating.

Fbreak . The load occurring at the moment immediately before the final fracture of a tensile test specimen divided by its original cross sectional area

Fmax. The maximum load occurring in a tensile test divided by the original cross sectional area of the specimen

Flash . Very thin material produced by escape of liquid metal from the die cavity (usually unintentionally). Most flash is produced at the parting line but some can be produced by metal being forced into the small clearance between ejector pins and the die cavity.

Gate . The position where metal enters the die cavity proper. The gate is always somewhere on the parting line of the casting, usually between 0.2mm and 0.6mm thick and its length depends on casting size and finish requirements. Castings requiring good surface finish require proportionately greater gate area (gate thickness times gate length)

Hot chamber diecasting . A process where the metal injection system is permanently immersed in liquid metal.

L 0 . The original gauge length of a tensile test specimen

Overflow . A pad of diecast metal produced from alloy that flowed through the die cavity during the injection process. Overflows serve two functions, they locally heat the die, usually with the intention of improving the surface finish of the casting, and they provide a location for ejector pins.

Parting Line . The line of separation between the two (or more) elements of a diecasting die. Also refers to the resulting witness line visible on the diecasting. Also referred to as the parting plane or split line.

Shredder . Process equipment used to fragment metal scrap, particularly scrap cars, to allow the materials to be sorted into their individual types

Sweating . A process for recovering scrap metals where the temperature of a load of mixed scrap placed on an inclined plane is slowly raised to sequentially melt the individual constituents of the scrap.

Sprue . The conical shaped initial runner section formed in the die with each shot in hot chamber diecasting. This material and any runners joining it to the casting(s) are remelted and reused.

Z pin . A modified ejector pin, with a Z shape ground into the head of the pin (as seen in elevation). This serves to retain the casting in the die until the ejector pin moves forward.