Alüminyum Basınçlı Döküm

The reasonableness of the design of die casting is related to the entire die casting molding process, in the design of die casting, should give full consideration to the structural characteristics of the die casting, die casting process requirements, try to minimize the occurrence of defects of the design of die casting in the die casting molding process, in order to the optimal design scheme to maximize the improvement of the quality of the die casting.

Reasonable design die casting wall thickness

1. Aluminum alloy die-casting structure design should give full consideration to wall thickness, wall thickness is of special significance in the die-casting process, wall thickness, and the whole process specification have a close relationship, such as the calculation of filling time, the selection of the speed of the inner gate, the calculation of solidification time, the analysis of the mold temperature gradient, the role of the pressure (the final pressure), the length of time to stay in the mold, casting ejector temperature and operating efficiency;
2. Designing the wall thickness too thick will result in external surface defects such as shrinkage holes, sand holes, air holes, coarse internal grains, etc., which will make the mechanical properties decrease and the quality of the part increase resulting in higher costs;
3. Design wall thickness is too thin will cause poor filling of aluminum liquid, and molding difficulties, so the aluminum alloy dissolution is not good, easy to appear casting surface filling difficulties, lack of material and other defects, and the die casting process brings difficulties;
4. Die casting with the increase of air holes, internal air holes, shrinkage holes, and other defects, so in order to ensure that the casting has enough strength and stiffness under the premise, should try to reduce the casting wall thickness and keep the cross-section of the thickness of uniformity.

Reasonable design of die-casting reinforcement

For large plane or thin wall die casting, its strength, and rigidity are poor, and easy to deform, then the use of a reinforcing bar can effectively prevent the die casting shrinkage, and fracture, eliminate deformation, enhance the strength and rigidity of the die casting, for too high columns, tables and other structures, can use reinforcing bar to improve the distribution of stress conditions, to prevent the root of the fracture, and at the same time reinforcing bar can assist in the flow of melted metal to improve the casting of the filler performance.
Reinforcement of the root thickness is not greater than the thickness of the wall here, the general thickness is designed for 0.8 ~ 2.0mm; reinforcement of the mold release slope is generally designed for 1 ° ~ 3 °, the higher the design of the mold release slope is smaller; reinforcement of the root need to add rounded corners, in order to avoid sharp changes in the cross-section of the part, and at the same time to assist in the flow of molten metal to reduce stress concentration in the parts, to enhance the strength of the parts, rounded corners are generally close to the wall thickness here; Reinforcement height is generally not more than 5 times its thickness, reinforcement thickness is generally required to be uniform, if the design is too thin, reinforcement itself is easy to fracture, if too thick, it is easy to produce depression, porosity, and other defects.

Reasonable design die-casting mold slope

The role of die casting mold slope is to reduce the casting and mold cavity friction, easy to take out the casting; Ensure that the die-casting surface is not strained, and at the same time extend the life of the mold. Die casting slope and the height of the die casting, the greater the height, the smaller the slope of the mold. In general, the outer surface of the die-casting mold out of the slope for the inner cavity out of the mold slope of about 1/2, but in the actual design, can be die-casting inside and outside the surface of the mold out of the slope design for the same, in order to maintain a uniform wall thickness, simplify the structural design.

Reasonable design processing allowance

Die casting design should try to avoid machining, machining will destroy the surface of the parts of the dense layer, affecting the mechanical properties of the parts; will make the die casting of the internal pores exposed, affecting the surface quality, but also increase the cost of parts. Die casting can’t avoid machining, one should try to avoid the design of large cutting amounts, and structural design as much as possible to facilitate the machine or reduce the machine area, to reduce the cost of the machine.

Die casting on the part of the higher dimensional accuracy requirements, or some plane surface roughness requirements, die casting process is difficult to meet the requirements, this time it is necessary to carry out subsequent processing, on this part of the structure, the design should try to reserve machining allowance. Die casting surface strength, hardness than the internal high, machining should pay attention to retain the surface of the densification, so the machining allowance can not be excessive allowance, machine plus too much is likely to produce porosity and external surface defects.

Aluminum alloy die casting spraying design

Die casting surface coating design generally uses a powder spraying process, the principle of electrostatic powder spraying: mainly through the electrode will paint polarization, and then the object to be sprayed with the opposite charge, in the electric field force under the action of the powder uniformly attached to the surface of the object. Powder spraying process features: powder electrostatic spraying does not cause air pollution, powder can be recycled to reduce the cost of material consumption, film performance acid, alkali, corrosion resistance is good.