Aluminum die castings are employed in practically every consumer and industrial product that is now on the marketplace. The engineer tasked with creating a new die casting is unlikely to know that the design of the product has a significant impact on the long-term cost of the product. For both the caster and the end user, a badly designed die casting will result in high tooling costs as well as quality issues. A proper die casting design will allow the metal to fill the cavity without enclosing any air, solidify fast, and eject from the die without causing any distortions. Continue reading to learn our top ten suggestions for completing a successful die casting project and .
1. Create a draft
The degree of taper or slope applied to cores or other sections of the cavity is referred to as draft. It is required on die casting features in order for the casting to be able to be removed from the mold. In the NADCA Product Standards Manual, numerous features are specified as standard drafts for various characteristics. This requirement, given as an angle, will vary depending on the type of wall or surface requested, the depth of surface applied, and the alloy used. It is usually sufficient to rotate the casting by 1-2 degrees in order for it to be released from the die without dragging or distorting.
2. Dates and times
When possible, keep key dimensions in the same die half as the die being manufactured. When they cross separating lines, the degree of dimensional diversity increases. It is possible to refer to the NADCA Product Standards Manual for information on typical tolerances that can be maintained on specific features. Throughout this essay, the NADCA Products Standards Manual will be referred to on a number of occasions. This is a "must have" tool for every die casting designer who wants to be creative. You should be able to obtain a copy from your die caster, or you can purchase one through the North American Die Casting Association.
3. Sharp corners and edges
Fillets should be used to break up sharp edges on all cuts of meat. Sharp edges induce stress risers in the die steel, which can lead to cracking and early failure of the die if not addressed. Sharp edges further reduce the metal's capacity to fill the hole completely and defect-free, as previously stated. The ribs that link intersecting walls and bosses should have a broad radius to allow for easy movement. This enhances metal flow and raises the overall strength of the item by a factor of three.
4. Wall thickness that is consistent
The designer should strive to keep the wall thickness of the castings as uniform as feasible throughout the process. Castings with thick walls will have higher levels of porosity, necessitating the use of more cooling in the casting die. Heat checking in the die steel will occur in the casting's heavy areas as a result of the weight of the casting. Metal savers should be employed whenever possible to eliminate bulk from thick portions of the casting, especially when the casting is made of aluminum. If you want more in-depth information, check out our blog post How to Make a Casting without Porosity!
Solidification simulation of an extremely hefty wall of a casting that remains liquid while the gate and remaining casting solidify is shown in this video clip. This section of the part will have a lot of porosity.
5. Ejector Pins
Ejector pins will be used by the die to force the casting out of the die in an equal fashion. The ejector pin placements should be taken into consideration when designing the item. The pins should be evenly positioned around the portion in order to ensure even ejection of the part. Ejector pins should be installed on bosses, ribs, or other structural characteristics of the part to ensure that it is not damaged. If ejector pins are placed on a thin wall of the casting, they have the potential to push right through it.
6. Final Machining and Finishing
Final machining will be necessary if your casting has features that cannot be physically die cast or if your casting requires extremely tight tolerances. It is critical to keep the amount of material removed from the workpiece to a minimum during the machining procedure. The larger the amount of material removed during machining, the more likely it is that porosity will be visible on the machined surface after it has been finished. Removing only the amount necessary to account for dimensional variability in the castings.