What is an Aluminum heat sink and what factors affect its quality?

There are different metals with different properties, some metals are used for luxury purposes such as diamond and gold, others are used for building purposes such as brass, nickel, steel, copper, and many more. Every piece of equipment, to work efficiently, requires a good building block. And while engineering important components it is extremely important to look at the qualities of the material that are going to be used and it is also important to keep a check on the factors that can affect the material, Aluminium in this case.

Aluminum is considered the best option for engineering heat sinks because it is cost-friendly, lightweight and most importantly has great thermal conductivity.

Which Metals Conduct Heat The Best?

Copper and Aluminium among other metals have the highest thermal conductivity. Before using metal in any sort of application it is very important to check the thermal conductivity of that metal. The rate of thermal conductivity helps to decide which metal should be used for a specific purpose. Aluminum is a great conductor of heat, which makes it useful for constructing heat exchangers. On the other hand, steel is a very poor conductor of heat which makes it useful for high-temperature environments. This is why Aluminum is preferred to be used in constructing a heat sink.

Thermal Conductivity

Heat transfers in three ways; radiation, convection, and conduction. Thermal Conduction is a process where two objects of different temperatures come into contact with one another and when they meet fast-moving molecules from the warmer object transfer the energy to the slow-moving molecules in the cooler object.

Aluminum heat sinks

Aluminum is considered beneficial for electrical device managers. It is a great metal to be used in the construction of critical power cooling systems. Improvement in extrusion profile technology has made it possible to engineer heat sinks which call for a blend of greater strength and lighter weight.

Aluminum in comparison with other metals such as copper has lower thermal conductivity but it is far too difficult to extrude them into the shape of a heat sink. Secondly, Aluminium is a lightweight metal, which is also another property that other metals do not possess.

Heat Sinks

Heat sinks are mainly used inside computers to cool down the CPU(Central Processing Unit), they are also used in lighting devices, LEDs, and power transistors.

Heat sinks are designed in a way to have a large surface area to maximize the contact with the fluid medium, such as air or liquid coolant to absorb heat and direct it away from the device.

Aluminum alloys are preferred to be used in constructing heat sinks. This is because Aluminium is lighter and cheaper than copper.

How does a heat sink work?

Computers heat up and if the heat is not removed from the device it can actually damage the entire system. To direct the heat away from the system it is necessary to install a heat exchanger. Heat sink directs the heat away from the computer, it does this by transferring the heat generated in the system to a fluid medium such as air or a liquid coolant, whereby it is directed away from the device. 

What is the purpose of a heat sink?

The purpose of a heat sink is basically the maintenance of the computer. Without a heat sink, the system can overheat and therefore can stop working efficiently. To ensure smooth working of the device it is important to install a heat sink to direct generated heat away from the system and prevent overheating.

Why is a heat sink important?

As stated above, a heat sink is vital for extending the life of a lighting device. It absorbs unnecessary heat and directs it away from the device. Heat sinks increase the efficiency of the device by removing the excess heat which is why it is an extremely important component. Without a heat sink, computers or other related devices can expire quicker. Heat sinks keep the system cool and provide a good working environment to the other components which heat up quite quickly.

Factors Affecting Aluminum Heat Sink Quality

Quality Requirements For Ingots

The blend of alloys in an ingot must be strictly monitored and controlled, for purification purposes. To make sure that the structure and properties are not imbalanced it is important to make sure that the alloys are homogenized. The surface of the ingot must be smooth and there must not be any sand. The end of the ingot must be flat.

Requirements For Die/Tool

The fins must be tough and strong and to make sure that it is achieved it is important to make sure that the quality of the steel die is reliable and it can go under great pressure during the extrusion process.

For tool heat treatment, nitrogen quenching is preferred. Nitrogen quenching can ensure the uniform performance of each part of the die. After the quenching is done three times tempering should be done to ensure that tool has hardened enough.

Reduce Extrusion Pressure

To prevent the fins from breaking extrusion pressure should be minimal. The extrusion force is related to the length of the aluminum rod, the resistance of the alloy against deformation, and the rate of deformation. The cast bar, therefore, must not be longer than 0.6-0.85. Homogenization can also greatly reduce the extrusion pressure. Therefore homogenization annealing can be considered greatly beneficial and is also necessary for ingot casting

Extrusion Process

Extrusion is a process used to engineer different products of a fixed cross-sectional area by pushing the desired molten material into a die of the desired size cross-section. First, to make an aluminum heat sink it is necessary to do the first trial die after that heat must be adjusted accordingly and each fin must be extruded properly and the pressure of the plunger must be below 8mpa. The temperature of the die must be related to the cast.

Conclusion

Summing it up, it depends on you how much you would like to spend on a heat sink. If you are looking for a lightweight metal that can work just like Copper then Aluminium is the best choice. Extruding Aluminum is very easy, just keeping an eye on little things such as nitrogen quenching is important. Moreover Aluminium is also pocket-friendly so it again is the best choice.