Aluminium Alloys

steel / aluminium alloy....????

Doesn't sound a very healthy mix. Corrosion against what?

Its called Stainless Steel - Aluminum not required.
If you want it light (like aluminum) and strong (like steel), then Titanium's your metal.

what is the material, which can give high corrosion resistance, when mixed with aluminium??????????????????

These metals are entirely different systems. At the temperatures that the steel would be liquid, the aluminum would be totally oxidized. If you ddn't mean as an alloy, Steel and aluminum will corrode as a galvanic pair.

Aluminum is added as a deoxidizer to steel to remove bubbles.

Iron is a troublesome contaminant of aluminum alloys.

Alloy creation is not Take one from column a one from column b. it requires depth of knowledge of thermodynamics, metallurgy, physical chemistry and the economic realities of cost of production. Corrosion resistance is another science unto itself with specific anodic/cathodic mechanisms and various chemical reactants.

WHat is the specific design problem, and an answer can be developed from the requirements?

Milo

Do you mean "bi-metallic" ? Steel and aluminium separately are not a good combination. I remember once talking to an official of the Mexican Navy who was saying how seaworthy the Aztec Class boats were. The only problem really was when it rained. Bimetallic corrosion.

I hope that I am not adding any confusion here with this comment, but modern cans for drinks APPEAR to be a mixture of alumium & some sort of iron for the can itself and the top appears to be aluminium alone....

The can itself is partially magnetic insofar that a magnet will stick on it, albeit with less force than you would expect for say a steel can.....

I had imagined that the metals were mixed under an inert gas or maybe its a steel can with Aluminium plating to stop corrosion....

I have not chemically analysed the can, it just looks and feels like Aluminium, but magnets stick on it!!!

Perhaps someone more learned in this area can clear up my missconception for once and all. Thanks in advance....

Andy, your observation is valid but not explained as you suggest. I doubt that the can is aluminum if it will attract a magnet. Better read the labeling on the can for its material content. Todays modern draw and iron 2 piece cans are made out of extremely light gage metal, either steel or aluminum, the decision of which is generally based on the commodity price differential between the metallic strip feedstocks. Most can lines can be converted to run steel or aluminum with very little adjustment. Often the product's 'premium image' is a determining factor, as aluminum seems to have more glamorous appeal to the consumer.

The light gage (thinness) of the steel may make it seem to be aluminum. Its low carbon content to assure sufficient ductility to be drawn into shape also is suggestive of what we think of as Aluminum properties, rather than our image of how steel behaves. The low mass and low carbon may also be factors explaining the weakness of the magnets' attraction to that particular product.The can ought to be labelled with its makeup somewhere in the area of the recyclable symbol. Take another look.

To the rest of the contributors, Electroplating, chemical conversion coating, or using other means to deposit and bond a metallic coating onto metal should not be confused with ALLOYING by technical people. Sales and marketing people perhaps, but not by those of us who are technicians/ engineers/managers working with processes. We really need to use our language as carefully as we use all of our other tools.

The design phase of an engineering problem starts with understanding of what is trying to be accomplished. Before that it is critical that all in the conversation share the same vocabulary. Alloying is NOT Plating. If we aren't careful about terms and terminology, who will be? Its a professional thing.

Milo

Basiaclly, a steel in contact with Aluminium, and with an electrolite present, will form a galvanic cell. The aluminium will then corrode sacrifically. In doing this the steel will be protected - look up galvanic corrosion and sacrifical anode protection.

If you want to coat the steel in aluminium then a 'pure' 1000 series alunimium is best, but it must be 100% coated! There is an electroplating process that does this and claims to have better corrosion protection that Cadmium plating!

The process I was thinking of is called 'Alumiplate' - see www.alumiplate .com

...and Cadmium plating is not very environmentally safe! Lots of poisonous chemicals if I remember correctly...

Whereas I would guess that Alumplate has a strong future.....as long as the chemicals are not so dangerous!

There are many alloys of aluminum, none of which use steel (which is another alloy of iron). Virtually any aluminum product one buys is NOT pure aluminum, but some alloy there-of. The MAG wheels which we put on our cars (back when I was a kid) were not made of magnesium per se. They were an aluminum wheel with a high amount of magnesium in the mix to give the wheel it's strength and corrosion resistance.

The aluminum alloy I use most of all is "6061" which has good anti-corrosion properties, or if you were to anodize the aluminum, you might want to use an alloy in the 2000 series, or if you needed to weld it, you might want to use a different series. Some metals mixed with aluminum to give different alloys are magnesium (mentioned above), copper, manganese, chromium, and probably others. To learn of the different aluminum alloys, I would check with one of the major aluminum manufactures (such as Reynolds Aluminum). I would bet that they would have literature describing the various alloys, probably on line.

Don't take what I have said above as bible as it is only off the top of my head. I haven't seriously looked at aluminum alloys in years.

Best of luck

Bill

Sciesis2 laid out the aluminum alloys very well. As for soda cans some companies use steel and aluminum but after the steel is stamped into the can form it is coated inside with plastic for corrosion resistance.

There are steel alloys with corrosion resistance such as corten which develops a slight film of corrsion on the outside and the corrosion stops there. It is used in outdoor projects from buildings to ships and cargo containers.

one of the best aluminium alloy used in ship building for it's corrosion resitance... http://www.matweb.com/search/SpecificMaterialText.asp?bassnum=NHOOG01n