Improvement measures for cracks in low pressure casting of auto parts

1) The reasonable design of the riser, the heat preservation sleeve and the casting pouring system constitute the riser system, which is also the channel for the liquid metal to enter the mold cavity from the crucible. If the riser is too long, the temperature drop of the liquid metal in the riser will be large, which will easily lead to the early solidification of the channel. So we should pay attention to the following points in the design of the liquid lifting system: first, we should shorten the distance between the metal level in the crucible and the gate as much as possible after combining the factors of equipment, mold, etc.; second, we should expand the thickness of the insulation layer, which can be achieved by increasing the diameter of the insulation sleeve. At the same time, the materials with better thermal insulation performance, such as aluminum silicate fiber felt, should be used in the selection of materials. Thirdly, in order to prevent the premature solidification of the riser, the diameter of the riser should be appropriately increased. It is very important to design the lifting system reasonably to prevent the cracking caused by the solidification of the lifting pipe when the casting is ejected.

2) The reasonable design of wheel structure combined with the formation mechanism of cracks shows that in order to prevent the occurrence of cracks, the design of wheel structure is particularly important. In the design, the reasonable fillet should be set to avoid the stress concentration caused by the sharp corner structure, and the structure with uniform section should be set to properly increase the mold temperature without casting defects.

3) Compared with the iron sprue sleeve, the ceramic sprue sleeve has the advantages of good heat preservation performance, no aluminum contamination, fine crystallization of the cap mouth, good overall crystallization, small comprehensive energy consumption, strong product competitiveness, etc., which can be used for the material of the sprue sleeve. But the iron sprue sleeve is not suitable because of many shortcomings.

Scroll to Top