aluminum castings at low pressure

Low pressure: 2 have

Low pressure casting is a well-known casting process. In particular, most aluminum wheels is manufactured by injection molding low pressure. By contrast injection high pressure of this method uses a pressure of only about 2 have.

fig2Figure 1 - Scheme low pressure casting technology of aluminum

Filling the mold accelerate through by feeding in compressed air holding furnace. The melt is fed upward along the tube profitable, which is submerged in the melt depth. This provides a smooth filling of the mold and the melt cleanliness. After that, as a mold filled, opposite the lucrative part starts solidifying metal. air pressure control in the holding furnace ensure complete filling of the mold. molding cycle is quite long due to the fact, that during the whole time casting solidification linked through profitable pipe with a large volume of melt in the furnace.

Molding automotive parts under low pressure

Casting, low pressure cast, for example, large V-shaped automotive engine cylinder blocks of hypereutectic aluminum alloys, Cylinder head and engine motorcycles.

fig1Figure 2 - Aluminum cylinder head,
cast by low-pressure casting

fig3Figure 3 - Aluminum company BBS Rim,
made by casting, low pressure

fig4Figure 4 - Aluminum V-shaped cylinder block,
cast by low-pressure casting

Machine for low-pressure casting

The mold usually has channels, through which is passed water or compressed air. This makes it possible to control the temperature of cooling conditions during solidification.

Directional solidification and pressurizing provide small volumes profitable part of the casting, a, so, less metal waste goes to remelting. In normal, gravity chill casting yield can be only 50 %, while for low-pressure casting it is about 90 %. This effect is shown in Figures 5 and 6: in injection molding, the profitable part is much smaller, than at chill casting.

fig5Figure 5 - aluminum wheels,
made by casting, low pressure.
The hub is visible a small profit center.

fig6Figure 6 - aluminum wheels,
manufactured by gravity die casting.
In the center of the hub and the rim of the large profitable part visible.

Low pressure die casting machine includes:

  • sealed holding furnace,
  • Equipment for feeding and compressed air control,
  • hydraulic crane for the installation and removal of molds.

Usually the machine for low-pressure casting works with one mold.

fig7Figure 7 - Machine for casting of aluminum alloys
Low pressure holding furnace with

A source: European Aluminium Association, 2002

See also

Cast aluminum wheels

Welding aluminum wheels