Aluminium Definition and 164 Threads

  1. 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...
  2. Artj0m

    Aluminium covered with gold submerged into water

    Homework Statement A piece of aluminum is completely covered with a gold shell to form an object of weight W. When you suspend the object from a spring balance and submerge it in water, the balance...
  3. N

    Thermal Expansion of aluminium

    Hi, The coefficient of thermal expansion for aluminium is 23ppm/C at 20C = 0.000023m per degree in temperature (C). Is this temperature: (1) the temperature of the air circulating around the material in the sun, (2) the temperature in the shade at that time of the day, or (3) the tactile...
  4. R

    How High a Temperature Can Naval and Aluminium Brass Withstand?

    I have come across some equipment constructed out of Naval Brass / Aluminium Brass. Apparently these are common materials for marine applications. e.g. desalination heat exchangers etc. Does anyone know how high a temp. these brasses can be used at? e.g. is 100 C OK? Also the crevice corrosion...
  5. KingCrimson

    Why does copper have a higher melting point than aluminium?

    Why does copper have a higher melting point than aluminium? Why does the melting point increase as you go down groups anyway? Aluminium has higher charge (+3) and a smaller radius, meaning that there is a higher charge density and thus stronger forces of attraction to the lattice. While copper...
  6. E

    AC electromagnet and aluminium levitation

    Hi all, I'm new to this forum as a member, but have come across some of the topics here via google in the past. I'm trying to build an AC electromagnet levitation device, to levitate a small piece of aluminium. My knowledge in physics is limited to popular science and interest, but I am pretty...
  7. F

    Quenching aluminium and aluminium alloy

    Hello. I got two questions. 1. Why does aluminium become more ductile if one rapidly quench it. 2. Why does aluminium alloys(not heat treatable alloys) become more ductile when it is rapidly cooled from solubility temperature. I have read through my notes from lectures, but could not find...
  8. C

    Why cheese need to be kept in aluminium foils

    Why cheese is always kept in aluminium foil.. like when it is exposed after one day without being wrapped in aluminium, it starts to change color and also starts getting moldy and so on.. why is it the case? why aluminium? how does it works? can someone explain it to me please?
  9. B

    How do eddy currents affect magnet movement through non-magnetic materials?

    Hi, what differences are if i use a pvc tube to build an actuator(solenoid with plunger) or alluminium? Alluminium can intensify magnetic field? but the plunger will stick with alluminium? or solenoid will have less force?
  10. K

    Aluminium Block immersed in water beaker

    Homework Statement physical reasons for the relationship between weight change(100CC beaker with water and when you dip aluminum block in water ) and apparent loss in weight of the aluminium (Aluminium block weight using spring balance and when that block immersed in water) Homework Equations...
  11. N

    Find the Best Glue for Aluminium Foil - Buy in Bulk!

    I need a recommendations on a glue to stick aluminium foil. Due to the size I need a product that can be brought in larger quantities rather than in small tubes; like a tub of wood glue or wallpaper paste. I'm asking because aluminium is reactive and I need something that will stick, but...
  12. B

    Why is sodium carbonate more thermally stable than aluminium carbonate

    Sodium carbonate will not decompose in the presence of heat. This is because sodium is a very reactive metal, and hence forms very strong bond with the carbonate ion. In contrast, aluminium is not as reactive as sodium. Hence the bond by aluminium is weaker, and aluminium carbonate will...
  13. G

    Determine the thickness of aluminium using γ-rays

    Homework Statement [/b][/B] Hi all, I have been given a mini-project to complete which involves a block of aluminium which is stuck to a piece of wood and taped so that where the aluminium and wood touch is unknown. I have been told that I need to design an experiment to measure the thickness of...
  14. E

    Bayer's Process for extraction of aluminium

    In Bayer's process in the digester both water soluble sodium aluminate and sodium silicate are formed. After that my textbook says cooling the sodium aluminate it crystallizes to to give aluminium hydroxide and sodium hydroxide. My two questions are, one, in the digester alumina reacts with...
  15. C

    Absorption coefficient of aluminium for microwaves

    I am looking for an exact value of absorption coefficient of aluminium for microwaves, but I can not find it in the internet. Anyone knows where I can find it?
  16. F

    Aluminium has no negatively charged particles?

    Q: "A graduate student tells you that he has observed a Schottky defect in a sample of pure aluminium. Explain why it may take a long time for this graduate student to get his Ph.D" A: "Pure aluminium has no negatively charged particles, so a Schottky effect can not occur." So I know a...
  17. L

    Aluminium Solution Treatment/Precipitation Hardening

    I am currently doing an experiment on 2xxx series AL. After solution treatment, the strength and hardness dropped. can i account it due to its micro-structure? (i explained it saying that due to the alloying elements being dissolved in the aluminum. Without the effects of the alloying elements...
  18. H

    Heat gained and lost by aluminium and water in thermal equilibrium

    Homework Statement A physicist pours 100g of water at 100'C into a 20g aluminium cup which already contains 50g of water at 20'C. The final equilibrium temperature of the water is 71.847. C(water)=4186J/kgC C(aluminium)=900J/kgC 1. the amount of heat lost by the hot water 2. the amount...
  19. S

    Literature Review- Aluminium Ring

    Hi there, I'm a university student and am stuck regarding a literature review for my individual project. I was given a schematic sketch of the setup of my experiment that showed a force acting on a hollow ring, and a strain gauges attached on the ring measured strain for the set force. I was...
  20. C

    Coefficient of friction aluminium on aluminium

    Hello I'm new here and to be quite honest not sure if I'm posting this in the right section, so apologies up front if I have this wrong. Basically I was wondering if anyone has any idea on why the dynamic coefficient of friction for aluminium on aluminum is greater than the static coefficient...
  21. L

    Comparison between aluminium and stainless steel

    I am looking for a paragraph on each metal on the comparison of aluminium and stainless steel under the heading: Manufacturing Methods: What processes are available to turn the raw material into products and how do the processing methods differ? Regards, Lockyphysics
  22. R

    Most probable speed of Aluminium

    Homework Statement Figure 1 shows a type of apparatus for investigating the speed distribution f (v) of molecules in a gas. Molecules emerge into a vacuum chamber from an oven held at a constant temperature T, and are collimated by slits into a parallel beam directed towards a pair of discs...
  23. S

    Inflate aluminium tube to increase it’s strength?

    I’m designing and hope to build a human powered helicopter (HPH) and am wondering if pressurising a thin walled aluminium tube by filling it with compressed air would strengthen it’s structural properties. Hope this is the right place to post this.
  24. M

    Wood vs aluminium stiffness. What doesn't add up?

    AFAIK, the wood used for aircraft structures should have a specific stiffness, that is specific Young's modulus and bending strength, somewhat higher than aluminium (see attached image). If that is the case, why wood aircrafts are generally more subject to aeroelastic effects compared to...
  25. S

    Need help related to heat, water and aluminium

    Homework Statement I need help at identifying what forumala's to use to calculate the following (Density of Aluminium 2770kg/m^3 An aluminium plate has a mass of 5kg and a surface area of 2m^2. The temperature of the plate is 450°C. The plate is immersed in a container of water of which...
  26. S

    Which electrolyte can I use for electrolytic etching of Aluminium

    Which Electrolyte can I use to etch Aluminum without generating toxic gases , I currently use 1200ml Water, 1200ml (30%-33% HCl) , 1200ml(68% HNO3) , 80ml(50% HF)
  27. E

    Heat Transfer Rate of 2 Heating Coils on Aluminium Plate

    Homework Statement ==================== <---- aluminium plate ⁣⁣⁣⁣⁣⁢⁢⁢⁠⁡⁡⁢⁢⁢...O .....O... <---- heat coil(O) Given an aluminium plate put on 2 heating coil(O), assuming no heat loss, how much is the heat transfer rate from the coil to the plate? Put the power of each coil as W...
  28. P

    How Do I Design an Aluminum Rod to Meet Specific Engineering Requirements?

    Hi guys, I'm studying my first semester in engineering, I was giving the first assignment in my material science class which I'm not so sure on how to get started on. The assignment was to ask us to design a aluminum rod which has the following specification: 1) Withstand an applied force...
  29. N

    Winding Copper wire / strip on Aluminium body

    Hello All, Greetings. I am new to this forum. I am working for a heater project, in which we use plastic (PA66) over molded on aluminum (6061-T6) body for melting corrosive liquids (similar to sea water). The Aluminum body is heated by means of Positive temperature coefficient material (PTC)...
  30. C

    High Emissivity Paint for Aluminium Surface

    Hey, I am making a furnace...which uses Aluminium material. Does anyone knows a paint which can be used for applying on Aluminium Surface and which works upto 500 degree Celsius and has high emissivity.
  31. B

    Why Doesn't Cooking Chicken in Aluminum Foil Cause an Explosion?

    Straight off of one of my textbooks: "Cooking a chicken with pure aluminium foil should be a dangerous activity. This is because the aluminium metal would react with the steam given off from the chicken to produce aluminium oxide and hydrogen... BANG! Can you explain why this does not happen...
  32. A

    How does a thin sheet of aluminum impact capacitance in a circuit?

    Homework Statement As shown in the figure, a very thin sheet of aluminium in placed in between the plates of the condenser. Then the capacity (a) Will increase (b) Will decrease (c) Remains unchanged (d) May increase or decreas Homework Equations Dielectric strength of a metal. The Attempt...
  33. nukeman

    Quick question about Aluminium ? How to find its oxidation state ?

    Homework Statement I am struggling a bit with naming compounds. Al2(Cr2O7)3 Now, I know its aluminum dichromate, and the way to find this was KNOWING the oxidation state of Al being +3 - How am I suppose to know that? How do you find that out when all you have is a basic periodic...
  34. J

    Can one burn aluminium wires using an electric arc?

    Could one burn aluminium wires by striking up an electric arc between them and then feeding them towards each other as they are consumed (like an arc light)? I assume the aluminium oxide would be burnt off as a vapour by the high temperature of the electric arc and thus would not inhibit the...
  35. J

    Running a vehicle by burning aluminium?

    Apparently aluminium has the highest energy density per unit volume of any material. It can be smelted from ore or recycled oxide using green electricity. People have made batteries using aluminium but they have problems like getting gunked up with Aluminium hydroxide etc. How about burning...
  36. L

    Examining aluminium foils stopping potensial on <0.98c fast electrons

    I got a Geiger-Muller counter, and a radioactive source. The source is a Sr-90/Y-90 source, which emits highly energetic electrons, the highest energy is around 0.98c. The space between the source and counter is approximately 10 cm. I am not operating in vacuum! The assignment I am doing is...
  37. S

    Thermal Expansion Aluminium Problem

    A brass ring of diameter 10.00 cm at 19.9°C is heated and slipped over an aluminum rod of diameter 10.01 cm at 19.9°C. Assume the average coefficients of linear expansion are constant. (a) To what temperature must the combination be cooled to separate the two metals? Brass=19 x 10^-6...
  38. O

    Why magnet cannot attract aluminium?

    As we know magnet can attract iron, but not aluminium, does anyone have any suggestions what make aluminium behave differently in term of molecule structures? such as Electrons, Photons Neutrons ... Thanks in advance of any suggestions
  39. Z

    Mass absorption coefficient of aluminium

    I was conducting an experiment, and we had to use a radioactive source and a Geigor counter, in conjunction with aluminium plates. Using the data we produced we had to graph an absorption curve and obtain a value for the mass absorption coefficient of aluminium. Then we had to compare this...
  40. L

    Dust aluminium atracted to magnet

    Hi Sorry I'm not good in physics at all. I have the following dust problem becoming attached to Nickel coatings. from what i know Nickel can become magnetic but aluminium should not be attracted to magnets. I did an experiment to confirm if the nickel coat is acting as magnet in...
  41. K

    Aluminium strengthening with carbon?

    Aluminium strengthening with carbon?? Hi , Is it possible to strengthen aluminium with interstitial strengthening by carbon?I couldn't find any aluminium alloy with carbon content.What is the problem behind alloying of carbon with aluminium?
  42. G

    What is the reason for using aluminium foil to wrap the food items?

    aluminium is a good conductor of heat, but still it is used so that food remains warm. what is the reason behind it?
  43. Telemachus

    Coefficient of rolling friction steel over aluminium

    Hi there. The thing is that in my laboratory project me and my companion tried to determine the rolling coefficient resistance for a steel ball rolling over an inclined plane of aluminium. Everything is fine till there, I've donde almost all the work. The thing is that I wanted to reference...
  44. K

    Shouldn't aluminium oxide be reactive?

    Once exposed to air, aluminium would form a layer of aluminium oxide, which would render it unreactive in acids. But, aluminium oxide is an amphoteric oxide. Shouldn't it be reactive in acids?
  45. S

    Maximum bending moment in aluminium alloy beam

    I have three questions and need to calculate the magnitude of the maximum bending moment 1) A 4 m long aluminium alloy beam, simply supported at its ends, carries a central concentrated load of 2 kN. The T-cross-section of the beam (see Figure A2) consists of a rectangular flange and web...
  46. R

    Reflectivity of ALuminium Foils

    Can Anyone tell me the exact THERMAL reflectivity if aluminium foils used at home?
  47. L

    Standing waves, aluminium, speed of sound

    1. I am a mathematician trying to understand a physics experiment where an aluminum rod is held in the middle and struck with a mallet. The rod is then placed next to a microphone, the sound recorded and the frequency determined using Audacity. Working backwards, one determines the speed of...
  48. kandelabr

    All about aluminium tetrafluoride

    Hello. I can't find any data on aluminium tetrafluoride. I am looking for its reaction with water, formation enthalpies, temperatures and anything/everything else. Could someone give me at least a hint where to look at, a material database, a book, website, anything...? Thanks!
  49. G

    Aluminium bar cold forming calculation

    I'm working on a problem that involves calculating force required to form a component. The problem is as follows (diagram attached): A round aluminium bar, with the initial diameter d0 = 36 mm, has to be cold formed into the component shown in using a combined forward/backward extrusion...
  50. B

    Convincing a female friend to buy an aluminium bicycle

    So one of my friends is buying a bicycle and I'm trying to convince her to plump for an aluminium model over some ridiculous 'retro' steel thing. I want to illustrate how aluminium allows for lighter structural members even taking into account the wider diameter tubes that ensure similar...
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