Thread: on the replacement for the perenties

Some intersting results from 4wd action mag posted by bob10. Something to keep in mind is that the alloy rims supplied for military vehicles may well be very differnt to those supplied either as a standard or aftermarket alloy rim. Also, the 4wd action mag results certainly show that there is considerable variation between alloy rims and between steel rims, and that alloy rims can easily be as 'robust' as steel rims. Most of us on here are of course primarily interested in Land Rover rims, and it is most unlikly that the 4wd action mag actually tested Landie rims, but never the less, still useful information.

Cheers
KarlB

Originally Posted by Celtoid

The alloy would be 'softer' too wouldn't it....thus limiting it's collateral penetration power?!

We tend to think that alloy rims are largely aluminium (not magnesium), which is true, but there would be a variety of other metals alloyed with the aluminium and in different proportions for different reasons. This is no different from the situation with our Land Rover body panels which are an alloy of 92% aluminium, 7% magnesium and 1% manganese, that goes by the trade name of Bermabright. I am not a metalurgist, but I would imagine alloying titanium with the aluminium would make it much harder but at considerable monetary cost. So I don't think alloy rims have to be softer than steel but I would assume they usually are for cost reasons. There may be ways to work harden the surface as well.

Originally Posted by KarlB

I am not a metalurgist, but I would imagine alloying titanium with the aluminium would make it much harder but at considerable monetary cost. So I don't think alloy rims have to be softer than steel but I would assume they usually are for cost reasons. There may be ways to work harden the surface as well.

Karl - sorry, but it doesn't quite work like that. i.e. - you can't determine the properties of an alloy based on the properties of the constituents.

e.g. lead/tin solder has a melting point much lower than either lead or tin.

Hardening aluminium is generally the opposite of hardening steel. e.g. heating up then cooling down quickly hardens steel but anneals (softens) aluminium alloys.

Most aluminium alloys are surface treated/hardened. Aluminium also tends to surface harden over time as it ages.

Originally Posted by isuzurover

Karl - sorry, but it doesn't quite work like that. i.e. - you can't determine the properties of an alloy based on the properties of the constituents.

e.g. lead/tin solder has a melting point much lower than either lead or tin.

Hardening aluminium is generally the opposite of hardening steel. e.g. heating up then cooling down quickly hardens steel but anneals (softens) aluminium alloys.

Most aluminium alloys are surface treated/hardened. Aluminium also tends to surface harden over time as it ages.

I'm not surprised. Metallurgy seems like a black art to me.

Cheers
KarlB

I have a metalurgist friend I use for desiging engine components and he say this is why we do it and I just say ok.

Originally Posted by KarlB

We tend to think that alloy rims are largely aluminium (not magnesium), which is true, but there would be a variety of other metals alloyed with the aluminium and in different proportions for different reasons. This is no different from the situation with our Land Rover body panels which are an alloy of 92% aluminium, 7% magnesium and 1% manganese, that goes by the trade name of Bermabright. I am not a metalurgist, but I would imagine alloying titanium with the aluminium would make it much harder but at considerable monetary cost. So I don't think alloy rims have to be softer than steel but I would assume they usually are for cost reasons. There may be ways to work harden the surface as well.

Mmmmm....OK....LOL.

I was actually making the point that the ADF may want the rims 'softer' (in relative terms) to steel....so that fragments are less damaging. Some of the explosion's energy would be absorbed as the flying alloy compresses against other objects (eg other vehicles, etc). Effectively negating some of the exploding energy (and penetration power) as apposed to becoming part of the bomb, as steel fragments do.

Kev.

Originally Posted by Celtoid

Mmmmm....OK....LOL.

I was actually making the point that the ADF may want the rims 'softer' (in relative terms) to steel....so that fragments are less damaging. Some of the explosion's energy would be absorbed as the flying alloy compresses against other objects (eg other vehicles, etc). Effectively negating some of the exploding energy (and penetration power) as apposed to becoming part of the bomb, as steel fragments do.

Kev.

I'd guess the outcome would be about the same if you were hit by flying fragments of either a steel wheel or a aluminium wheel, let alone all the other bits of the vehicle that would be flying in every direction.

cheers,
Terry

Originally Posted by TerryO

I'd guess the outcome would be about the same if you were hit by flying fragments of either a steel wheel or a aluminium wheel, let alone all the other bits of the vehicle that would be flying in every direction.

cheers,
Terry

To a soft squashy human maybe Terry...LOL...but not to other things maybe or the guys hiding behind them....full metal jacket bullet versus standard lead bullet I suppose would be a good example.....maybe

That is of course if the rims are really that much softer than steel.

Cheers,

Kev.