The quality of the casting, as well as the feasibility and simplicity of the manufacturing process, are heavily influenced by the die casting structure. Die casting has a structure that is similar to investment casting's production characteristics, so it is an example of a reasonable investment casting structure. It is frequently necessary to set the process rib and hole on the investment casting according to the needs in order to ensure the quality of the investment casting in the die casting production process, so the reference size of the process rib design is an application example of the process hole. Die casting parts are capable of casting extremely complex parts. Several parts assembly parts and weldments originally produced by others can be directly cast into one investment casting after some structural improvements in order to improve production efficiency and accuracy in the process of use. The pouring temperature of metal mold casting should be properly controlled during the casting process. If the pouring temperature is too high, the cooling will be slow and gradual, the product will crystallize coarsely, and its mechanical properties will be low, making pinholes, blowholes, and other defects easy to form. If the pouring temperature of a metal mold casting is too low, defects like insufficient pouring and cold shut will result. As a result, the casting temperature is controlled based on the casting structure and process characteristics, but the casting limit is kept to a minimum. The shrinkage rate in the die casting process will directly affect the quality of the casting, so we should set the shrinkage rate in advance and constantly modify the size of the metal mold in the casting process design and mold design.

When determining the casting process plan, the specific die casting parts are analyzed and a reasonable process plan is chosen in order to ensure the quality of die casting parts, improve labor productivity, and reduce costs.

It's a catch-all term for holes of various sizes and shapes found on the surface and inside of castings. Air hole, shrinkage cavity, shrinkage porosity, and other factors are considered.

1. Air hole die casting cavity defects caused by gas. It has a smooth surface and is mostly pear, round, or oval in shape. Large holes often appear in isolation on the surface of aluminum castings, whereas small holes appear in groups.

2. A combination of gas shrinkage porosity, dispersive porosity, shrinkage cavity, and shrinkage porosity forms a type of casting defect.

3. Pinholes are generally precipitated pores that are distributed across the cross section of the die casting in the size of a needle. It has a negative impact on casting results.

4. The dispersed pores on the casting surface are arranged in groups. It's usually visible on the casting's surface and can be removed after 1-2mm of machining.

5. Subcutaneous pores are pores that are scattered beneath the surface of the casting. The reactive pores created by the reaction of liquid metal with sand mold are referred to as reactive pores. It's most commonly discovered after machining or heat treatment.

6. A large amount of gas produced during the choking pouring process cannot be discharged smoothly, causing boiling in the metal liquid, resulting in a large number of pores in the die casting, as well as incomplete defects.

In die casting, pinholes are always a problem. Although pinholes are not a unique defect of resin sand casting, they have a significant impact on die casting quality and yield. The following are the primary methods for preventing pinholes:

1) As much as possible, increase the cooling rate of alloy liquid by using chill iron, chill sand, or even a metal mold; 2) Improve the melting quality of liquid aluminum, set a ceramic filter screen, or increase vortex directly lifting out for ladle to reduce hydrogen content and alumina inclusion in liquid aluminum; 3) For aluminum die casting, the melting temperature should be kept below 750°C, and the pouring temperature should be kept as low as possible; 4) The liquid aluminum modifier is replaced with antimony, titanium, and other modifiers, rather than sodium salt, which is prone to pinhole defects. 5) If the chemical composition meets the technical requirements for zllola alloy, the magnesium content should be reduced as much as possible, and the silicon content appropriately increased; 6) Aluminum ingots and other raw materials with low gas and inclusions and high metallurgical quality should be chosen, and the amount of recycled materials (waste castings) should be kept to a minimum of 15%. 7) Reduce resin sand core and coating gas generation by strictly controlling the amount of resin below 1.0, adding new sand in the proportion of sand, and other methods; 8) The baking temperature of water-based coatings is strictly controlled, and the baking temperature is increased from 150-1800C to 180200C, with a baking time of no less than H2. The cores above H8 should be dried again after drying; 9) To ensure smooth filling of molten metal, various casting process measures such as bottom injection, large gate basin, and open gating system were used. 10) Check for die casting and sand core exhaust, such as by adjusting the air outlet riser, changing the dark riser to an open riser, pricking the air outlet, and so on.