The tag has no usage guidance.

learn more… | top users | synonyms

-1
votes
0answers
25 views

Would a black copper bowl full of water in a hot, sunny room absorb enough heat to evaporate the water?

I'm looking at making my conservatory more humid, it gets a lot of sun and gets very, very hot. If I were to put a black copper bowl in the room full of water would this be a good metal for ...
3
votes
1answer
137 views

Do Shape Memory Alloys (SMA) work harden?

We had a piece of this thin Shape Memory Alloy in class, (I think it was called nitinol, but I think thats a brand name) the teacher showed how it is very flexible and springy, and will return to it's ...
0
votes
2answers
48 views

If two pieces of the same type of metal touch in space, will they bond and be permanently stuck together? [duplicate]

Yesterday I was watching discovery channel, on a program they said that 'if two pieces of the same type of metal touch in space, they will be permanently stuck to each other.' Is it true..? If yes... ...
17
votes
1answer
294 views

Third-order susceptibilities of metals?

Can anyone point me to a source for measurements of the third-order nonlinear electric susceptibilities $\chi^{(3)}$ of various metals? Specifically in relation to the AC Kerr effect, so measurements ...
3
votes
1answer
32 views

What are the effects of compositional changes in a thermocouple's junction?

We use thermocouples (type B) to measure the temperature of metals (Fe, Ag, Pd, etc) in a furnace under pressure. We weld two thermocouple wires together using an arc welder. This junction then comes ...
0
votes
1answer
412 views

Malleability in metals

I am trying to understand malleability in metal as a result of the micro structure. I am focusing on the metals of antiquity (in order of decreased malleability): Gold, Silver, Copper, and Iron. While ...
1
vote
0answers
27 views

High pressure deformation of metals

Does copper undergo elastic recovery after being exposed to high pressures (above 30 GPa in a diamond anvil) at room temperature?
0
votes
2answers
47 views

Copper density modification

Can you increase the density of a material surface (metal) by surface treatment? For example commercial copper. If we take the ordinary OF copper (99.95%), I would expect not to have the tabulated 8....
0
votes
0answers
23 views

crystal lattice modification

Can the lattice of a copper with FCC structure be altered, even microscopically? Copper has 0.361 nm lattice constant but can it be altered by external force, say neutron impact?
1
vote
3answers
59 views

Is there a way to measure the thickness of a metallic plate of order of micrometers?

I have a $5 cm×5 cm×? \mu m$ copper plate. Where '$?$', the thickness of the plate, is really small (about 30um). Is there anyway using physics to calculate the thickness? Update: Sorry I forgot ...
3
votes
2answers
37 views

Why chromium is more brittle than iron at room temperature?

Why is chromium more brittle than iron? I understand that both of them are BCC at room temperature. Is it to do with the grain size, and why is it different between the two metals?
0
votes
0answers
10 views

How long is the surface migration length of adatoms deposited by thermal evaporation in vacuum?

The deposition of metals through thermal evaporation involves the process of adatoms migrating on the substrate before its kinetic energy decreases to a certain point or before encountering a cluster. ...
0
votes
1answer
43 views

Electric current in metal objects

This might be a stupid question, but I can't find the answer anywhere. Why don't objects such as rings that people wear (which are made out of metal) have electric current in them? As far as I know ...
0
votes
1answer
129 views

Magnetization of soft iron and steel

I was reading and I saw that the steel becomes permanent magnet whereas iron becomes a temporary magnet after magnetization during magnetic induction. Why does soft iron make temporary magnets and ...
6
votes
1answer
60 views

What happens at the point of welding iron?

What is the physics behind welding iron? It is obviously the electricity that causes the two metal parts to fuse but what is the role of the welding rod and why is it said to damage your eyes when you ...
0
votes
0answers
41 views

Why does thicker aluminum do better at reflecting wifi

I have performed a experiment based one the ability of aluminium reflecting wifi radio waves. I have found out that the more aluminium foil i put on my reflector, the better result I can get. I did up ...
0
votes
1answer
35 views

Is it possible to levitate large objects through diamagnetic levitation?

I am currently building a diamagnetic levitator with a strong neodymium magnet, two slabs of bismuth (a diamagnetic material), and a small neodymium cube to levitate. However, I was wondering if it ...
1
vote
1answer
95 views

What is the desest material on earth? [closed]

Apart from the elements, do we know of materials that are denser? I.e. can an alloy be denser than the sum of its compounds, for example if the new lattice packs denser than each of the compounds it's ...
1
vote
1answer
27 views

What determines photoelectric yield

Is there any difference between the photoelectric yield of different metals apart from the threshold wavelength? To be more clear: Will metals with the same work function emit the same amount of ...
0
votes
1answer
40 views

Photoelectric effect on charged plate

As far as I know, to observe the photoelectric effect, one has to expose a metal surface to high-energy radiation. But what happens if the surface has a surplus of electrons? What is the energy needed ...
3
votes
1answer
51 views

Is the photoelectric effect 'Ionising Radiation'?

According to the definition on Wikipedia, ionising radiation is radiation which has sufficient energy to remove an electron from an atom. So a high energy gamma ray is definitely ionising, but visible ...
1
vote
0answers
9 views

Hopping integral for Hydrogen chain

When calculating a hydrogen chain in the tight binding approx., one comes across the hopping integral: $<m+1|V_{m+1}|m>$ Where $|m>$ is the 1s-Wavefunction at position m and $V_m$ is the ...
0
votes
1answer
45 views

How to reduce size of bracelets using physics?

My mom has a set of bangles (bracelets) made of gold like the ones shown in the picture. Problem is the size (diameter) of these bangles is a bit more than required. If she goes to a goldsmith he cuts ...
3
votes
2answers
56 views

Why are metals worse conductors when heated?

When metals, (such as in circuits), are heated, their ability to conduct electric current is hampered. Why is this? Does the transition towards liquid disrupt a metal's ability to conduct, or is ...
0
votes
0answers
26 views

How can a metal and an insulator have high dielectrics yet one is conducting and one is insulating?

I don't get it: insulators are referred to as dielectrics. The higher the dielectric the higher the insulation(?). But the dielectric constant of metals is considered infinite. Aren't they supposed to ...
4
votes
1answer
85 views

Resources in space, and their distribution

I'm making a video game in which the economics of an interstellar civilization is important. What I'm wondering is, how are resources in space distributed? Since everything ultimately comes from ...
1
vote
0answers
9 views

Effective interaction between electron-magnon in ferromagnetic transition metals

I wonder whether there are classical references on an effective theory of electron-magnon interaction in itinerant ferromagnetic metals?
46
votes
8answers
55k views

Will a hole cut into a metal disk expand or shrink when the disc is heated?

Suppose you take a metal disc and cut a small, circular hole in the center. When you heat the whole thing, will the hole's diameter increase or decrease? and why?
1
vote
1answer
28 views

Find the spectral distribution of a metallic reflection given electron configuration

If I have the electron configuration for a metallic element, how do I find the spectral distribution of its specular reflection? For example, for gold (2,8,18,32,18,1) I should get a greater ...
2
votes
1answer
35 views

When electrons absorb energy and get excited then jump to a higher energy level do they do so in steps or do it directly?

So I was reading about Fermi surfaces. One of the first things that is obvious is that energy excitations happen at the boundary of the surface as the electrons deeper inside the surface do not have ...
15
votes
3answers
824 views

Why would different metals glow red at different temperatures?

According to everything I've been taught about incandescence and black-body radiation, and some quick Googling to confirm I'm not crazy, just about everything, regardless of composition, should start ...
0
votes
1answer
63 views

How is work function related to oxidation?

Low work function metals, such as Li and K, oxidize in ambient conditions, whereas high work function metals such as Au do not oxidize. In chemistry there's activation energy and reaction rate ...
2
votes
3answers
124 views

How to measure thickness of an ultra-thin metal layer?

I have a sample of a metal (aluminum/oxide) layer with a gradual thickness ranging from monolayer to 100nm. This layer is deposited on a transparent substrate, like glass. How can I measure this ...
1
vote
1answer
29 views

Are all FCC structures ductile?

Doing research on crystal structures and the effects of Ductile to Brittle transition at different temperatures. Results of this test proved aluminium to be a brittle structure, which I know to be ...
0
votes
1answer
21 views

Estimating fraction of radiant energy absorbed by a metal

I have a couple of texts on thermodynamics and radiant energy but am finding it difficult to figure out from these how energy absorption and reflection work. The area of interest is heating ferrous ...
2
votes
2answers
236 views

Is this a correct description of bonding in a metal?

I am reading the paper "Twenty five years of Finnis-Sinclair potentials" by Graeme Ackland, Adrian Sutton, and Vasek Vitek, Philosophical Magazine 2009, 89, 3111-3116. It is a review-type article ...
4
votes
2answers
28k views

Why is stainless steel a poor conductor of electricity?

I recently had a metal plate put in my shoulder and was wondering why stainless steel isn't a good conductor (At least I hope it isn't). Does the alloy just lack free electrons? Why is that?
2
votes
1answer
2k views

What makes some aluminium alloys so strong while remaining light?

Compared to cast iron, for example, certain alloys of aluminum have both strength and weight advantages. How can aluminum be so strong while being so light?
0
votes
2answers
90 views

How to attract liquid metal with magnets

I would like to know if there is any way that I could make mercury or another liquid metal be attracted or repelled by magnets. Absolutely any solution would be okay with me. For example... can I ...
4
votes
2answers
349 views

Is there any relation between temperature dependence of resistance and fermi energy in metals?

Given that the resistance varies linearly with temperature in metals, is there any way we can calculate the Fermi energy from this information?
0
votes
0answers
60 views

absorption spectrum of aluminum

I am trying to find the absorption spectrum of aluminum but only can find reflectivity of it and other optical properties. It is easy to find absorption of aluminum oxide, foams etc. but not possible ...
0
votes
0answers
79 views

Model of the nucleus as fermi gas

I am taking an introductory course in modern physics, and am reviewing some of the exams from previous years. In our course, we studies the Fermi gas model for electrons in a metal. In one of the ...
1
vote
1answer
52 views

Can a magnetic field weaken aluminum?

I'm wondering if there is any reason to suspect that applying a magnetic field to a piece of solid aluminum would weaken it structurally in any way. The application is that I would like to put a stir ...
1
vote
1answer
17k views

Dielectric constant or permittivity of metals

I'm wondering what the dielectric constant or permittivity of metals is --particularly copper. Do metals have an infinite permittivity?
3
votes
1answer
80 views

What happens to the electron density in a metal during an electric discharge?

Suppose we are able to see into a grain of metal at the boundary between the grain and air (perhaps along one of the faces of this cube): (Source: Wikimedia Commons.) This image does not show the ...
2
votes
0answers
174 views

Could a falling office tower cause the melting of its iron or steel support structure? [closed]

Discussion on META: Questions related to geopolitical events Suppose you have an office tower, weighing around 300,000 metric tons, and has a height of ...
7
votes
4answers
5k views

How does positive charge spread out in conductors?

I know that when there are excess positive charges in a conductor, for example, a metal sphere, the positive charges will spread out over its surface. However, I am confused about how this excess ...
2
votes
0answers
84 views

What is “Accumulated plastic strain rate” in Current yield Norton law?

I'm doing FEA of steel under high strain rates and using Elasto-ViscoPlastic material model, with Von-mises yield criterion along with Isotropic hardening. The strain rate sensitivity is addressed by ...
0
votes
0answers
19 views

Are magnets attracted to mu-metal?

Are magnets attracted to mu-metal? Be aware that when watching videos of mu-metal they may have metals that are attached to the mu-metal and are attacted to magnets. Please don't get them confused.
0
votes
1answer
57 views

Can a magnetic ball “diffract” around a metal object?

Consider a magnetic ball falling through a copper pipe. It falls slower than it would if it wasn't near any copper. We can use this to determine that the closer a magnetic ball is to copper, the ...