Points needing attention in producing aluminum heat sink

Aluminum alloy is widely used in heat dissipation equipment because of its light weight, beautiful appearance, good thermal conductivity and easy processing into complex shapes.

Aluminum heat sinks mainly have three types: flat wide shape, comb shape or fishbone shape; Round or oval, custom heat sink is radial outside; Dendritic.

The utility model is characterized in that the distance between heat sinks is short, a groove shape is formed between two adjacent heat sinks, and its depth width ratio is large; The wall thickness difference is large, the general heat sink is thin, and the thickness of the bottom plate at its root is large. Therefore, it brings great difficulty to the mold design, manufacturing and production of heat dissipation profile. Some of the heat sink aluminum profiles with small size and symmetrical shape are easy to produce. Most of the heat sink profiles are flat and wide, with large overall dimensions, and some are asymmetric. The groove depth width ratio between heat sinks is very large, which makes it difficult to produce. Several problems need to be paid attention to in order to successfully produce heat sink profiles.

Reduce extrusion force. In order to prevent die tooth breakage, the extrusion force should be reduced as much as possible, which is related to the length of ingot, the resistance of alloy deformation, the state of ingot, the degree of deformation and so on. Therefore, the casting rod of extruded heat dissipation aluminum profile should not be too long, which is about 0.6 ~ 0.85 times the length of normal casting rod. Especially when testing the mold and extruding the first casting rod, in order to ensure the smooth production of qualified products, it is best to test the mold with a shorter casting rod, that is, a casting rod with the length of the normal casting rod (0.4 ~ 0.6) times.

Extrusion process. The key to the production of heat sink profile is the first die test of extrusion die. If possible, you can first do simulation test on the computer to see whether the working belt of die design is reasonable, and then test the die on the extruder. The first die test is very important. The operator should make the main plunger move forward and slowly move forward under the low pressure of less than 8Mpa when pressing up. It is best for someone to look after the die outlet with the light of the flashlight. After each heat sink of the extrusion die evenly extrudes the die hole, it can gradually pressurize and accelerate the extrusion. When continuing extrusion after successful die test, pay attention to control the extrusion speed and achieve stable operation. When producing heat sink profiles, pay attention to the heating temperature of the die to make the die temperature close to the ingot temperature. If the temperature difference is too large, due to the slow extrusion speed during upward pressure, the metal temperature will drop, which is easy to produce mold blocking or uneven flow rate.