High-precision radiator aluminum alloy shell extrusion molding technology

[Foshan,June 19th]Aluminum Alloys are ideal materials for manufacturing heat-conductingaluminum alloy profiles and pipes due to their excellent electrical and thermal conductivity and excellent plasticity. 

There are many types of aluminum alloy heat transfer extrusions, and the classification methods are diverse, including classification by heat transfer method, surface treatment, variety and shape. These classifications together constitute the rich diversity of aluminum alloy heat transfer materials. Among them, radiators are one of the important applications of heat transfer extrusions, and the optimization of their performance is of great significance to improving the overall heat transfer efficiency.

Aluminum alloy radiator material
In the production of aluminum radiator profiles, some products with small size and symmetrical shape are relatively easy to produce. However, most radiator profiles are flat and wide, with large and asymmetrical dimensions, and the grooves between the fins have a large depth-to-width ratio, which makes production difficult. Therefore, comprehensive control is required from aspects such as ingot casting, mold and extrusion process to ensure smooth production of high-quality radiator profiles.

6063 aluminum alloy has been widely used in radiator manufacturing due to its good extrudability, thermal conductivity and mechanical properties. The key technologies for the production of aluminum alloy radiator profiles mainly include the preparation of high-quality ingots, the selection and design of mold materials, the reduction of extrusion pressure and the optimization of extrusion process.

Effect of extrusion process parameters on mechanical properties of heat sink

1. Extrusion temperature

As the extrusion temperature increases from 460℃ to 540℃, the tensile strength and yield strength of the aluminum heatsink show a trend of first increasing and then decreasing. When the extrusion temperature is 460℃, the tensile strength and yield strength of the heat sink are 208N/mm² and 175N/mm², respectively. As the temperature increases to 520℃, the tensile strength and yield strength of the sample increase to 246N/mm² and 214N/mm², respectively, reaching a peak. However, when the extrusion temperature is further increased to 540℃, the tensile strength and yield strength of the sample drop to 230N/mm² and 203N/mm², respectively. This shows that appropriate extrusion temperature helps to improve the mechanical properties of the heat sink, but too high a temperature will lead to performance degradation.

2. Extrusion speed
The extrusion speed also has a certain influence on the mechanical properties of the radiator. As the extrusion speed increases from 0.5m/min to 2.5m/min, the tensile strength and yield strength of the radiator also show a trend of first increasing and then decreasing. However, compared with the extrusion temperature, the effect of the extrusion speed on the mechanical properties is relatively small. When optimizing the process parameters, the appropriate extrusion speed should be selected according to the actual production needs and equipment capacity.

3. Extrusion ratio
The extrusion ratio refers to the ratio of the cross-sectional area of ​​the extruded billet to the die outlet area. As the extrusion ratio increases, the tensile strength and yield strength of the radiator also show a trend of increasing first and then decreasing. When the extrusion ratio increases from 10 to 13, the mechanical properties of the radiator reach the best state; and when the extrusion ratio further increases to 14, the mechanical properties begin to decline. Therefore, when optimizing the process parameters, a suitable extrusion ratio should be selected to ensure that the radiator obtains good mechanical properties.

Requirements for ingots and molds of aluminum alloy radiator Extrusion Profiles

1. Ingot quality requirements

To ensure the quality of aluminum alloy radiator extrusion profiles, the impurity content in the ingot must be strictly controlled to ensure the purity of the ingot. For 6063 aluminum alloy ingots, the content of elements such as Fe, Mg, and Si should be strictly controlled. In addition, the ingot must be fully homogenized to ensure uniform organization, performance, and chemical composition. The surface of the ingot should be smooth and free of impurities such as segregation nodules or sand, and the end face should be flat and the cutting angle should be within 3mm to avoid problems such as mold blocking or poor profile forming during the extrusion process.

2. Mold quality requirements

The design accuracy and manufacturing precision of the radiator profile mold are crucial to ensure smooth extrusion. Given that the mold has many slender teeth and needs to withstand huge extrusion pressure, each tooth must have both high strength and toughness. Therefore, high-quality steel, such as H13 steel or similar performance materials, should be selected during the mold manufacturing process. At the same time, the use of processes such as vacuum furnace heating and high-pressure liquid nitrogen quenching can ensure uniform mold performance, and the hardness is maintained between 48HRC and 52HRC through three temperings to maintain sufficient toughness and prevent mold tooth breakage.

In addition, a well-designed die structure is also crucial for the smooth extrusion of aluminum radiator profiles. For flat and wide comb-shaped radiator profiles, a guide die with a small center and large sides should be designed to guide the metal to flow to both sides, reduce the extrusion pressure of the working zone and distribute it evenly. At the same time, according to the characteristics of the large difference in wall thickness of the radiator profile section, the design of the die working zone also needs to be adjusted accordingly to maintain the uniformity of metal flow.