Design specification for die casting machine

Update:28 Aug 2020

Casting mold means that in order to obtain the structural shape of the part, the structural shape of the part is made in advance with other easily formed materials, and then the mold is placed in the sand mold, so that a cavity with the same structural size as the part is formed in the sand mold. Then pour a fluid liquid into the cavity. After the liquid is cooled and solidified, a part with exactly the same shape and structure as the mold can be formed. The casting mold is an important part of the casting process.

The design of die-casting parts must take into account the wall thickness of the die-casting parts, the fillet and demolding angle of the die-casting parts, the reinforcement ribs, the minimum distance between the holes and the holes on the die-casting parts, and the rectangular holes and grooves on the die-casting parts. There are seven aspects of machining allowance for inserts and die castings.
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1. Design specification for casting fillet

Generally, all parts of the die casting should have rounded corners (except at the parting surface), which can make the metal flow smoothly when filling, and the gas can be easily discharged, and it can avoid cracks due to acute angles. For die castings that need to be electroplated and painted, the rounded corners can be evenly plated to prevent paint buildup at sharp corners. The fillet radius R of die castings is generally not less than 1mm, and the minimum fillet radius is 0.5 mm.

2. Design specifications for inserts in die castings

First, the number of inserts on the die-casting part should not be too much; secondly, the connection between the insert and the die-casting part must be firm, and it is required to slot, bulge, knurl, etc. on the insert; thirdly, the insert must avoid sharp corners , In order to facilitate the placement and prevent the stress concentration of the casting. If there is serious electrochemical corrosion between the casting and the insert, the surface of the insert needs to be protected by plating;

Finally, heat treatment should be avoided for castings with inserts to avoid volume changes caused by the phase change of the two metals and loosen the inserts.

3. Design specifications for the wall thickness of die castings

Thin-walled die castings have higher strength and better compactness than thick-walled die castings. In view of this, the design of die castings should follow this principle: the wall thickness should be reduced as much as possible on the premise of ensuring that the casting has sufficient strength and rigidity. And keep the wall thickness uniform.

Practice has proved that the wall thickness design of die-casting parts is generally 2.5-4mm, and parts with a wall thickness of more than 6mm should not be produced by die-casting process. The performance of the impact of too thick and thin walls of die castings on the quality of castings: If the walls of the castings are too thin in the design, the metal will not be welded well, which will directly affect the strength of the castings and cause difficulties in forming;

When the wall is too thick or severely uneven, shrinkage and cracks are easy to occur. On the other hand, as the wall thickness increases, defects such as porosity and shrinkage inside the casting will increase, which will also reduce the strength of the casting and affect the quality of the casting.More About :Auto parts aluminum die casting