Each aluminium alloy has distinct physical features. They make it appropriate for certain applications. For instance, some alloys are perfect for specialist tubing. You can then choose services like tube reduction to adapt it to suit the application.

Heat treatment is something to consider because you can utilise it to fine tune a metal’s features. It consists of the controlled heating and cooling of an object, in whole or in part. You alter its microstructure, ultimately influencing its attributes.

Heat treating steel is something you might be familiar with. Yet, aluminium has a far lower melting point and greater thermal conductivity. This impacts how you can treat it. We’re going to discuss some of the options you have for heat treating aluminium here, so read on to find out more.

Which alloys can you heat treat?

You can only treat certain aluminium alloys. Manufacturers perform these treatments to impart enhanced features over the as-manufactured condition. For example, a treatment can relieve internal stresses, improve hardness, increase ductility, and strengthen alloys.

In general, you’re able to heat treat numerous aluminium alloys from certain alloy series to strengthen them. These include 2XXX, 6XXX, 7XXX, 8XXX, and, in some instances, 4XXX. Chemical composition is the primary reason why some alloys are heat treatable and others aren’t. Specific elements show improved solubility in aluminium at increased temperatures. Their atoms can redistribute themselves efficiently to generate an even distribution. Contact us if you need top quality tube reduction services.

Annealing

The first type of heat treatment we want to look at is annealing. It’s useful for counteracting cold working. When you work a metal, it tends to accumulate stress inside. This increases hardness and strength. Yet, it comes at the expense of formability and ductility, an effect called work hardening. It could be preferable for making an item stronger. Although, if you subject the object to more forming processes after, the lower formability can cause cracking. In the end, you’ll have to scrap the product.

It’s here where annealing comes in. The process works to reset the crystalline structure to relieve interior stresses. Also, it enhances formability. You’re then free to shape it efficiently with lower forces. More impressively, the metal will have higher deformation resistance. Something else annealing can do is relieve internal stresses within cast aluminium components. This stops future cracking.

The annealing procedure involves heating the alloy to a particular temperature. You hold it there for a set amount of time and cool it back to room temperature slowly.

Solution heat treatment

Another option is solution heat treatment. It’s a process similar to annealing. Rather than gradually cooling to room temperature though, you quench the object. Quenching, typically done in water, basically “freezes” the microstructure. This is before atoms are able to redistribute themselves. After you quench the aluminium, it’s possible to harden it via ageing. Something else quenching supplies is a window that permits you to do more forming procedures.

The main advantage with solution heat treatment is it will maximise the hardening alloying elements. This is so they don’t precipitate out until ageing has happened. The preferred temperature to obtain this solubility is a couple of degrees under the alloy’s melting temperature. Thanks to such a narrow window, it’s necessary to use very accurate furnaces to meet the right conditions. Talk to us if you want tube reduction.

Natural and artificial ageing

The third solution is natural and artificial ageing. Ageing is something that can occur naturally if you’ve solution heat treated the item. It will gradually increase both the hardness and strength. Once it begins, the alloy’s microstructure will begin to lock onto its final position.

For natural ageing, the majority of the hardening happens within 24 hours of treatment. However, it can take four or five days to reach the max hardness. Some alloys though can’t obtain their maximum strength through natural ageing only. Their solid solution components can’t completely precipitate. These alloys benefit from more heating to obtain full precipitation. Although, it’ll be a far lower temperature than that used for solution heat treatment.

The process where you age at higher temperatures is artificial ageing. It’s also called precipitation hardening. You heat the alloy to a particular temperature and you hold it there for 6 to 24 hours. Afterwards, you return to room temperature. The result is a stronger, harder material that is less ductile.

We can work with numerous tubes if you need tube reduction

At Multiform Tubes Engineering Ltd, we can work with tubes made from a wide range of materials. Besides aluminium, we have experience with copper, titanium, brass, and steel. No matter what project it is we’re tasked with, we aim to complete it to the highest standards.

So, speak to us if you need the foremost services for tube reduction. We can arrange it for various applications in different industries.