Information on Aluminium Gravity Die Casting Process
Gravity die castdie casting machineing
is one of the standard processes for the manufacture of high-integrity
automotive castings。 It represents proven and absolute precision
technology for the production of large batch quantities。 This process is
used in carousel casting units or in shuttle technique particularly for
the manufacture of engine castings。 Optimum heat dissipation from the
solidifying casting through the die leads to short solidification times。
This results in castings which have good mechanical properties,
especially after an additional heat treatment。
In addition to
producing ever more complicated cylinder heads for petrol and diesel
engines, this is also used for the manufacture of diesel engine blocks
with cast-in grey iron liners。
Process description
In processes, the melt is metallurgical treated in the holding furnace, which is positioned near the dies?
The
quantity of melt for one is transported in a ladle and poured into the
riser system of the mould by tilting the ladle。 The melt fills the mould
cavity smoothly from the bottom up until it appearsDie casting in the risers positioned above the casting。
In the example shown, thezinc die casting
casting of a cylinder head, the mould filling and solidification
Conditions can be influenced by the design of the gating system and the
risers in the top core。 Directional solidification can be forced by
using water cooling in the bottom of the die。
Low pressures die casting
Low pressure diezinc die casting casting is a well-known process, especially for aluminium wheels in passenger cars。 The processdie casting machine
is also used in the production of big V-engine blocks in hypereutectic
aluminium alloys and in the casting of air-cooled cylinder heads for
motor cycles。 Mould filling is controlled by regulatingDie casting
the pressure in the casting furnace。 The melt flows through the riser
tube which is positioned under the melt surface of the furnace and fills
the mould very smoothly with clean melt from the bottom upMulti slider die casting machine。
After mould filling, solidification starts from the opposite end of the
mould in the direction of the tube。 By increasing the pressure in the
casting furnace, good feeding is guaranteed。 Cycle times are long dueMulti slider die casting machine to the fact that the casting is connected to the big melt volume by the riser tube during solidification。
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