The Draft Angle of Aluminum Die Castings in the Die Casting Process
Draft angles
The draft angle of the die casting process refers to the taper or slope which is perpendicular to the casting. The surface of the die casting part perpendicular to the parting line of the mold needs to be drawn so that the die casting part can easily be removed from the mold core or cavity.
Why is the draft angle of die castings important?
The shrinkage stress of the die casting in the cooling and shrinking of the die casting process causes the die casting to stick to the mold core, and the resistance for demolding is generated when the die casting part is released from the mold. Reducing the resistance for demolding can make the part released easily from the mold core and prevent surfaces of the die casting part and mold core from being scratched due to friction caused by relative movement. In short, the die-cast draft angle must be the same as the demolding direction on the side of the casting.
How to design the draft angle?
(1) Take the problem of wall thickness into account. If the thickness difference is too great, it will affect the filling.
(2) Consider the demolding problem, which is very important in the practice of die casting. Such problems often occur in reality, which is much more annoying than the demolding of injection molding. Therefore, the setting of draft angle and calculation of movable and fixed molds should be paid attention to. The general draft angle is 1 to 3 degrees. The outer draft angle is smaller than the inner draft angle, considering the smoothness of demolding usually. The outer draft angle is 1 degree, while the inner draft angle is about 2 to 3 degrees.
(3) Considering the problem of mold design when designing; if there are multiple positions for sliding blocks, they should be set on the two sides. You'd better not put them in the lower position. Otherwise, problems will occur.
(4) There may be some special requirements for the appearance of some die castings, such as oil spraying, powder spraying, etc. At this time, it is necessary to avoid important appearance positions in the structure to facilitate the setting of overflow grooves for gates.
(5) In terms of structure, try to avoid the appearance of the structure that leads to the complex structure of the mold, such as having to use multiple sliding blocks or spiral sliding blocks.
(6) For parts required surface processing, please note that there should be some finishing allowance when the part is designed, but not too much. Otherwise, the operator who processes the part won't be happy with you. Also, the gas holes inside will be exposed. The best finishing allowance should be not greater than 0.8mm so that there won't be gas holes basically, because there is the protection of a hard layer.
(7) Another thing which needs to pay attention to is the selection of materials. Choosing ADC12 or A380 should be based on the requirements.
(8) Aluminum alloy has no elasticity, so it can only combine with plastics to make snap joints.
(9) Generally, deep holes cannot be made. Only make some dot holes when opening the mold, and then process it afterward.
Topper die casting company specializes in manufacturing aluminum alloy die castings such as lighting parts, zinc alloy die castings like locks and lock parts as well as parts for automobiles. If you need any die casting parts for your project, please don't hesitate to contact us.
The draft angle of the die casting process refers to the taper or slope which is perpendicular to the casting. The surface of the die casting part perpendicular to the parting line of the mold needs to be drawn so that the die casting part can easily be removed from the mold core or cavity.
Why is the draft angle of die castings important?
The shrinkage stress of the die casting in the cooling and shrinking of the die casting process causes the die casting to stick to the mold core, and the resistance for demolding is generated when the die casting part is released from the mold. Reducing the resistance for demolding can make the part released easily from the mold core and prevent surfaces of the die casting part and mold core from being scratched due to friction caused by relative movement. In short, the die-cast draft angle must be the same as the demolding direction on the side of the casting.
How to design the draft angle?(1) Take the problem of wall thickness into account. If the thickness difference is too great, it will affect the filling.
(2) Consider the demolding problem, which is very important in the practice of die casting. Such problems often occur in reality, which is much more annoying than the demolding of injection molding. Therefore, the setting of draft angle and calculation of movable and fixed molds should be paid attention to. The general draft angle is 1 to 3 degrees. The outer draft angle is smaller than the inner draft angle, considering the smoothness of demolding usually. The outer draft angle is 1 degree, while the inner draft angle is about 2 to 3 degrees.
(3) Considering the problem of mold design when designing; if there are multiple positions for sliding blocks, they should be set on the two sides. You'd better not put them in the lower position. Otherwise, problems will occur.
(4) There may be some special requirements for the appearance of some die castings, such as oil spraying, powder spraying, etc. At this time, it is necessary to avoid important appearance positions in the structure to facilitate the setting of overflow grooves for gates.
(5) In terms of structure, try to avoid the appearance of the structure that leads to the complex structure of the mold, such as having to use multiple sliding blocks or spiral sliding blocks.
(6) For parts required surface processing, please note that there should be some finishing allowance when the part is designed, but not too much. Otherwise, the operator who processes the part won't be happy with you. Also, the gas holes inside will be exposed. The best finishing allowance should be not greater than 0.8mm so that there won't be gas holes basically, because there is the protection of a hard layer.
(7) Another thing which needs to pay attention to is the selection of materials. Choosing ADC12 or A380 should be based on the requirements.
(8) Aluminum alloy has no elasticity, so it can only combine with plastics to make snap joints.
(9) Generally, deep holes cannot be made. Only make some dot holes when opening the mold, and then process it afterward.
Topper die casting company specializes in manufacturing aluminum alloy die castings such as lighting parts, zinc alloy die castings like locks and lock parts as well as parts for automobiles. If you need any die casting parts for your project, please don't hesitate to contact us.
