Aluminium or Steel

[redddraggon]

Why do people prefer aluminium cases? Obviously aluminium has a lower density and so the case will be lighter.

From a materials science perspective I don't see the point in paying the premium for an aluminium as I don't move the case around much and prefer the superior mechanical properties of the steel.

Obviously case design is the determining factor in the end, but why is aluminium so popular?

[saltynay]

aluminium is better at conducting heat. Easier to mod as it is softer. aesthetically pleasing

[staffsMike]

and its so much lighter!!

[redddraggon]

even tho Aluminium does have a far higher thermal conductivity, the effect is neglible compared to the steel as the thermodynamics of transfering the heat to the aluminium via convection is difficult. If the case had loads of its own fins to increase the surface area, but cases tend not to.

[redddraggon]

and its so much lighter!!

The density of Al is 1/3 that of steel, but the strength is also 1/3 of steel, but the cost is 3 times higher.

Surely Carbon Fibre Reinforced Plastic is the way forward for the high end market?

[saltynay]

even tho Aluminium does have a far higher thermal conductivity, the effect is neglible compared to the steel as the thermodynamics of transfering the heat to the aluminium via convection is difficult. If the case had loads of its own fins to increase the surface area, but cases tend not to.

HTPC cases often do I think aluminium is wasted with gaming towers as you have the large fans or water cooling

[Funkstar]

HTPC cases often do I think aluminium is wasted with gaming towers as you have the large fans or water cooling

Like mine

http://www.kustompcs.co.uk/acatalog/info_1276.html

17KG of aluminium, i wouldn't like to try this with 51KG of steel!

[redddraggon]

Like mine

http://www.kustompcs.co.uk/acatalog/info_1276.html

17KG of aluminium, i wouldn't like to try this with 51KG of steel!

you'd only need about 6Kg of steel for the same mechanical strength.

[saltynay]

but heat dissipation you would need a huge steel case.....

[jamena]

Aluminium doesn't need to be painted. It's easy to work with into weird and wonderful shapes. I believe the construction lines are easier and cheaper to reconfigure (i.e. after a year people are bored with your case so you change how it looks) All in all it's probably not a lot more expensive when it comes to the finished product. Plus it won't rust (well, not like steel) when you scratch it and you can always re-polish the surface if you're keen.

wrt strength and weight I'm pretty sure a clever design will keep the aluminium case strong enough without having to be 3 times thicker...otherwise why does Aluminium make for lighter cars? Must be some way to get around that neat little 3x1/3=1 as quoted above if indeed it is that simple a relationship?

That 17kg case could probably have been made more efficiently (in terms of heat dissipation) with lots of thinner fins but they'd have sliced up your fingers and bent too easily hence the thicker structural fins. That sort of case arrangement would work okay if the hot bits like the cpu were directly connected to the case (via a heatpipe for e.g.)

In a standard case most of the heat is expelled by shifting the air through it. The effect of the case being warmed inside and cooling outside is neglegible unless you have truly awful airflow.

I think it's comes down to the fact that Aluminium is easier to make into fancy shapes, isn't that much more expensive as a finished product, and gets Kudos for being Aluminium because steel's boring

[redddraggon]

I suppose I'm biased, what with being from a longtime steel working family. And at university I was always taught when selecting materials to justify not using steel.

[Funkstar]

That 17kg case could probably have been made more efficiently (in terms of heat dissipation) with lots of thinner fins but they'd have sliced up your fingers and bent too easily hence the thicker structural fins. That sort of case arrangement would work okay if the hot bits like the cpu were directly connected to the case (via a heatpipe for e.g.)

I'll get some photos taken of it all together sometime in the next couple of days. Graphics cad and CPU both use heat pipes and it works very very well.

You are right about the fins cutting fingers. It is difficult to move as it is, with thinner fins it would be a lot less sturdy and would be great at amputations

As for strength, i think it is a lot stronger per/kg than steel. But it isn't as hard and durable. The two things are very different.

[redddraggon]

As for strength, i think it is a lot stronger per/kg than steel. But it isn't as hard and durable. The two things are very different.

For an aluminium component to be the same strength as steel it would be roughly the same mass, but the volume of the aluminium component would be roughly 3 times greater. The "Strength" of Al 2024-T3 is 345MPa whereas a Stainless steel is 1310MPa. In this case the strength is the yield strength.

The ductility of the aluminium means that it is easier to process as you say.

[saltynay]

For an aluminium component to be the same strength as steel it would be roughly the same mass, but the volume of the aluminium component would be roughly 3 times greater. The "Strength" of Al 2024-T3 is 345MPa whereas a Stainless steel is 1310MPa. In this case the strength is the yield strength.

The ductility of the aluminium means that it is easier to process as you say.

but do you actually need the casing to be that strong??? It isn't like the casing is put through extreme pressures, temperatures or weights

[lanceuppercut]

Why do people prefer aluminium cases?

i like mine because its prettier than a plain steel case

[redddraggon]

but do you actually need the casing to be that strong??? It isn't like the casing is put through extreme pressures, temperatures or weights

I'm just biased, apart from my love of steel, I have the old fashioned opinion that if it's heavy - it's quality.