What is Aluminium: Definition and 163 Discussions

Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating.
Chemically, aluminium is a weak metal in the boron group; as it is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it is polarizing, and bonds aluminium forms tend towards covalency. The strong affinity towards oxygen leads to aluminium's common association with oxygen in nature in the form of oxides; for this reason, aluminium is found on Earth primarily in rocks in the crust, where it is the third most abundant element after oxygen and silicon, rather than in the mantle, and virtually never as the free metal.
The discovery of aluminium was announced in 1825 by Danish physicist Hans Christian Ørsted. The first industrial production of aluminium was initiated by French chemist Henri Étienne Sainte-Claire Deville in 1856. Aluminium became much more available to the public with the Hall–Héroult process developed independently by French engineer Paul Héroult and American engineer Charles Martin Hall in 1886, and the mass production of aluminium led to its extensive use in industry and everyday life. In World Wars I and II, aluminium was a crucial strategic resource for aviation. In 1954, aluminium became the most produced non-ferrous metal, surpassing copper. In the 21st century, most aluminium was consumed in transportation, engineering, construction, and packaging in the United States, Western Europe, and Japan.
Despite its prevalence in the environment, no living organism is known to use aluminium salts metabolically, but aluminium is well tolerated by plants and animals. Because of the abundance of these salts, the potential for a biological role for them is of continuing interest, and studies continue.

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  1. BriggsMason

    Is there an acid that could dissolve Aluminium & leave Copper alone?

    [Mentor Note: Two thread starts merged into one] I need to remove the Aluminium heat fins from a CPU heat extange lined around some copper water heat pipes. I could use a saw, cnc or grinder to remove them, but it seems that this way could be cleaner, and less probable to ruin the heat pipes...
  2. lforster02

    Calculating theoretical thickness while anodising aluminium oxide

    I am trying to calculate the theoretical thickness of an anodised coating. I know all values apart from I am unsure whether to use 2e or 6e for the amount of electrons. Anode reaction as follows: 2OH = H2O + O + 2e the aluminium reactions preferentially with the one O atom, using equation: 3O...
  3. abdulbadii

    On aluminium as vise / clamp material

    This's slight confusion as productions/markets have aluminium material for making up a vise clamp Is it really going to workable/viable and which type aluminium could reliably be as vise clamp ?
  4. M

    What's the load capacity of 6 aluminium posts?

    Hello First time here! I have acquired 6 aluminium boxes they are 2 metres in length, they are 150mm x 150mm square and the walls are 3mm thick (they are also powder coated). My plan is to use all 6 boxes upright as posts for a covered pergola or in other words a fancy BBQ hut, so I will be...
  5. F

    Stainless Steel and Anodised Aluminium

    Hello engineers, Is it ok to use stainless steel bolts in an anodised aluminium clamp? I know that I should avoid using stainless steel with plain aluminium because of risk of corrosion. Also, what torque would you recommend that I apply to an M10 stainless steel bolt in an anodised aluminium...
  6. S

    Mesh hole size calculation for RFID signal blocking

    For a project I am currently facing a problem that I find difficult to solve. I am developing a shielding portal that uses a mesh to blocks UHF RFID signals. I would like to use aluminium mesh due to it being lightweight and its attenuation properties. The frequency of UHF RFID signals in the...
  7. D

    Tracking thermal expansion of an aluminium load cell

    Hi all, I am having trouble getting repeatable results from a linear regression formula that simply uses temperature vs load cell output especially with rapidly increasing/decreasing temperatures. This appears to be a result of the thermal co-efficient of our temperature sensor being almost...
  8. S

    Aluminium anodizing pore membrane

    When anodizing aluminium (or Titanium) a dense hexagonal pattern of microscopic pores is formed, and you can get a pretty high aspect ratio with them. But the illustrations always show the oxide layer with pores on top of a pure aluminium layer. But can you oxidize a thin sheet of material so...
  9. E

    Young's Modulus and the Poisson Ratio of Aluminium

    Hi. I've been given these sets of value. How do I calculate Young's modulus and Poisson Ratio from these set of value. I tried to create a stress vs strain graph but the graph does not look like a common stress vs strain graph but instead more of a y=x graph. The diameter of the rod is 10mm and...
  10. G

    Vacuum Tank Query (Aluminium, Carbon Fibre, etc, Composition)

    Hi, I'm hoping this will be a fairly easy question for someone on here to answer. If I wanted to make a (small?) vacuum tank (basically a hollow cylinder capped with two similarly hollow hemispheres - like so: (===)), how thick would the walls of the tank need to be for it to withstand the...
  11. nilsvoorkamp1

    Friction: aluminium on carbon

    I need the coefficient of kinetic friction for movement between greasy aluminium on carbon. It's nowhere to be found on the internet. Thanks in advance!
  12. H

    Need stress value of aluminium for project work

    Summary: I am not a physics student but I really need to prove that aluminium will not deform 10m underwater Hi I am doing a project of a product which will sink underwater. It will be a sealed cylindrical vessel, length 2m, width 1m, thickness 0.02m. Aluminium 6061t will be used with a yield...
  13. I

    Hole in an aluminium plate and that plate is heated

    the radius of the hole should decrease from my perspective but the book says that the radius of the hole will increase. I am not able to understand why??
  14. K

    Is Zinc alloy or Aluminium alloy better?

    Which alloy is better resistant to corrosion and less easy to get scratched and the paint fall? For kitchen cupboard handle. Thanks a lot.
  15. Phi_lip

    Construction Making a gong stand - will aluminium tubing be strong enough?

    Hello everybody, I am planning to make a gong stand using tube clamps and aluminium tubing, but I am unsure whether the tubing will be strong enough. I like the idea of using aluminium, to aid with portability of the stand. As the stand will be used to play the gong itself, which will move back...
  16. A

    Maximizing Strength: Choosing the Right Aluminum Tube Diameter for Marquee Poles

    I'm planning on making marquee poles out of aluminium tube. I did so last year and they worked well, but they flexed slightly under tension. To correct this flex, I want to use slightly different size of aluminum tube. I used 4" tube, with a ¼" wall, at a length of 30'. Will the tube be...
  17. C

    Electrical Minimum conduction voltage between aluminium plates exposed to air?

    Hi, just thinking about a possible project and it may involve bolting aluminium plates together and putting a very small voltage across them. If I take two plates of aluminium, leave them to oxidise in air (we all know Al forms a surface layer) then is there a minimum voltage that will flow...
  18. N

    Construction Making seat mounts from aluminium

    Hi all, I'm hoping one of you clever people can help me with whether my seat mounts will be suitable or not. I've done loads of googling and forum searches, but I just can't get my head around it. I have a 630mm gap that I need to bridge and mount a seat too, so the seat will be directly...
  19. S

    Producing other metals with thermite reactions

    Hello all, I am curious as to whether it is possible to create aluminium from a thermite reaction. Thermite, as standard, uses aluminium and iron oxide, which react together when burnt to create a blob of molten iron. I would like to achieve a similar result, but with a blob of molten...
  20. Joe591

    Possible Causes for Hole in Radiator Tank

    What would cause a hole to form in the top aluminium tank of a radiator of an earthmoving machine. The tank material is 6mm thick and is made from 1050 aluminium plate. The material around the hole has bubbles almost like pitting corrosion or like somebody went and took a flame to it. The rest...
  21. T

    Molten Aluminium: Health Risks & Safety Tips

    As I mentioned in subject, I want some molten aluminium. Is it dangerous for human health to do it? Should i use some protection?
  22. Liquid Metal Embrittlement - Gallium vs. Aluminium

    Liquid Metal Embrittlement - Gallium vs. Aluminium

    Bringing gallium and aluminium together has some interesting and occasionally rather explosive results, as Dan found out in this little tale from the prep room at the Royal Institution, UK.
  23. N

    Induction: Electromagnet and Aluminium Ring

    I need some help with this task, I am stuck. 1. Homework Statement An aluminium ring is placed on top of an elctromagnet. a. The electro magnet is connected to AC. What will happen with the aluminium ring? Motivate your answer. b. What will happen with the ring if the electromagnet is...
  24. B

    Aluminium corrode and aircraft fuselage

    Describe how Aluminium can corrode or degradein Aircraft Fuselage. And methods for avoid degradation in Aircraft Fuselage. I don't know where to find any information on it at all
  25. A

    Aluminium weight buoyancy problem

    An aluminium weight (B) is placed on top of a 0.472 kg wooden block (A) that is floating in water as shown below. The wooden block has a density of 533 kg.m-3 (3 s.f.). Calculate the required mass of the Aluminium weight to just fully submerge the wooden block as shown in the diagram. The...
  26. P

    Magnets on Aluminium and Brass

    I was torn between Materials, Mechanical and Electrical Engineering but could not think which would be the best home for this question so I’ve put it here for now. I tore open an old exorcise bike that used a big fly wheel with magnets on a lever and a strip of copper around the rim. I could...
  27. Tejasp56

    Aluminium 6061 - T6 Extrusion

    Hello, Can anybody help me for below problem? We have done extrusion of 6061 material and we achieve T6 hardness after 8-10 hour edging process. Now the problem is...when we have check mechanical properties of aluminium then it is not matching with T6 mechanical properties. Can anyone help...
  28. S

    How to make: 20% Aluminium Chloride Hexahydrate in Acohol?

    I want to make an antiperspirant myself, i am a bit confuse about the hexahydrate part, for instance i let AlCl3 powder in open for a few days to absorb humidity what is the next step? i am an art student but i wasn't that bad in chemistry in school, it was just my lack of interest in this...
  29. M

    A Permittivity of aluminium

    Consider a metal such as Al. How do we look up or determine the relative permittivity of the metal? Suppose we have some known incident frequency, say about c/500nm for visible light. We can look up the bulk plasma frequency (3.7 PHz for Al), can it be calculated from that? For context, what I...
  30. S

    Anisotropy of cold rolled aluminium

    Sorry for my poor english. I did tensile test of aluminium(purity more than 99%. 1000series). The three specimens had tensile directions of 0, 45, and 90 degrees for each rolling direction. strength(both yield and UTS)is higher degree closer 0 degree. and %elongation is too. but modulus of...
  31. E

    Heat flow through aluminium rod

    Homework Statement An Aluminium rod has a diameter of 40mm. and is 750mm long. If the temperature difference between the ends of the rod is 100C . Take the thermal conductivity of Aluminium to be 235 Wm-1K-1 Homework Equations k * A * ΔT / L The Attempt at a Solution 235 * 0.097 m * 100 /...
  32. L

    Cooling Steel Die for Contact Cooling of Aluminium - Advice Needed

    Hi, I am designing a system to cool aluminium through contact cooling. I have a steel die with 9x 20mm diameter cooling chambers. Water is pumped through the chambers which cools the steel die and hopefully the aluminium sitting on top of it. I am looking to find the temperature of the...
  33. kamhogo

    Shear: What would be the equation for ''pure'' torque?

    Homework Statement We had this elementary experiment in class. An aluminium rod is fixed at one end and at the other end you have a disk. You hand increasingly heavy weights on the disk and measure how much the rod shears (twists). We were asked to make a graph of the shear torque vs. angle of...
  34. S

    Aluminium Oxidation: Reusable Portable Circuit Solutions

    I have watched many videos of aluminium air batteries and it got me wondering. Could this same process work if you stored the aluminum in vacuum and exposed it to oxygen? For example: A high surface area aluminium plate is in a glass bulb under high vacuum. A copper lead connects to the...
  35. S

    How to calculate how much an aluminium tube can hold?

    Hi all, I'm going to make a roller shaft for a roller mixer. I will be using a aluminum tube of length 900mm placed horizontally and the two ends will be help in a bearing. An another pipe will be placed side by side to the first pipe with a bit of space in the middle and held the same way as...
  36. marcophys

    What lives in washing machines and eats aluminium alloy?

    The washing machine stopped spinning, so I dismantled it. Here's what I found: I'm thinking it might have become a big battery, as the steel drive shaft was embedded in the alloy drive bracket, which in turn had 6 studs bolting it to the stainless steel drum. It was all enclosed in the sealed...
  37. M

    Aluminium vs Copper in power lines

    Hi, I have a question concerning the use of aluminium in power lines. I know that it's lighter than copper and thus cheaper, which is the main reason we prefer it above copper. But in fact alumunium has a lower conductivity than copper. Why is it then that one kg of aluminium can carry twice...
  38. L

    Deflection of an aluminium plate

    Dear Engineers, I have a rectangular plate (3 x 2 m) made of aluminium (12 mm thickness). I also have a evenly distributed load of 2500 kg spread over the entire plate. How can I calculate the maxiumum deflection at a certain point on the plate? The plate is fixed in all directions on the...
  39. C

    Threaded Bolts in Aluminium - Strength Info Needed

    I'm looking for any information about the typical strength for bolts that are threaded into aluminium. I've tried googling them but I'm having hard time finding information; I've tried looking through machinery's handbook and it doesn't seem to be showing the information for this specifically...
  40. H

    IP 65 rated enclosure with heat dissipation

    Hi there! Is there any ip65 rated enclosure material with electronic components inside but with no holes/cutouts that can act as a heat sink without overheating while the product is operating? Enclosure will need to be wall-mounted outdoors, it could be made out of die-cast aluminium which...
  41. P

    Calculating Maximum Pressure for T6 Aluminium Cylinder

    Hi guys, The imagine the picture attached is a cross section of a cylinder. How would I work out the maximum amount of pressure this can be exposed to before the metal shears off at the location labelled "2mm thick"? Lets say the following material is used: T6 Aluminium Ultimate Tensile...
  42. J

    Aluminium and Barium Nitrate reaction

    1. Homework Statement Homework EquationsThe Attempt at a Solution I chose B, because I thought adding more OH- would cause the reaction to shift to the left, and a low temperature would slow the rate of reaction, but the answer is A, why pH 7?
  43. S

    What is the req.thickness of sheet metal to prevent buckling

    My project involves making a 5 ft*3 ft*4 ft (l*b*h) aluminium/stainless steel sheet metal box at the back of a slow moving pedal vehicle. There is no load on the sheet metal, except from small vibrations from road travel. My question is: 1. What gauge of sheet metal thickness would be enough...
  44. R

    Mass of aluminium in a sample

    Hello, sorry to bother again. A sample containing Al reacts with an aqueous solution of 5.05 g HCl producing 5.70 L of H2 at 20°C and 742 mmHg. Find the mass percent of Al in the sample assuming hydrogen behaves like an ideal gas.I can't again understand this exercise, because I've never done...
  45. G

    How to divide pressure applied at a point on a rod?

    Hello Every one I want to know how the pressure applied at a particular point on a rod will be equally divided underneath of the rod. What materials are good to achieve this kind of situation?
  46. spareine

    Aluminium oxide surface and conductivity?

    Aluminium surfaces are protected by a thin aluminium oxide layer. The oxide layer supposedly does not conduct electricity. However, when measuring the contact resistance between the test pen of a multimeter and the aluminium, this resistance is always small. Why? Is the oxide layer easily punctured?
  47. M

    Aluminium embossing roller

    Hi I have a aluminium hand roller for embossing numbers onto aluminium. When I pass the aluminium plate through the roller, I end up with a kind of banana shaped piece of aluminium. Any suggestion on a jig I could add to the aluminium rollers Thanks
  48. R

    Bending and welding Aluminium 2mm sections

    Hi I am planning to make a light weight camera mount for my RC multicopter (drone). Issue is due to irregular shape of the camera, need for the mount to be light weight, and setting up a small angle of inclination (5-10 degrees) the only solution I have come up with is to use light weight thin...
  49. A

    Highest frequency of sound waves in a thin aluminium rod

    Homework Statement Estimate the highest possible frequency (in Hertz) and the smallest possible wavelength, of a sound wave in aluminium due to the discrete atomic structure of this material. The mass density, Young's modulus, and atomic weight of aluminium are 2.7x103kg m-3, 6x1010 N m-2, and...
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