The study of how the properties of matter arise from its structure at all scales and of how processing can be used to modify those properties (often in pursuit of a specific application).

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69 views

Mullins effect in the elastic material

I was thinking on a experimental question, but I couldn't get the answer: How can we measure how the Mullins effect influences in the pressure inside a balloon? (I mean that, if there is a formula, ...
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1answer
73 views

Does the magnetic anisotropy state only have two possible directions?

Wikipedia says "The magnetic moment of magnetically anisotropic materials will tend to align with an easy axis". Does this mean that it is completely impossible to orient the magnetic moment with any ...
5
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1answer
270 views

What would happen to a submarine coated in water repellent

I saw the article about laser-etched hydrophobic metal, and it got me thinking, how would a submarine function differently if coated as such? Would it move faster, sink completely, be unable to move ...
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1answer
160 views

How much weight would I need to put on the end of a tube to break it?

Say I have a tube with a circular cross-section made from some material (for an example, I'd like to use acrylic). I support it horizontally from one end and hang a weight from the other end. How ...
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1answer
163 views

Applications of partial differential equations in material science [closed]

I've been asked to find a partial differential equation that has applications in material science. However we are not allowed to use the heat equation. I have found Fick's laws (basically the heat ...
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1answer
188 views

Plasma frequency

I have a neutral plasma and I need to solve Maxwell equations given the charge and current densities on the plasma. In order to do it I need to know the electrical permittivity $\varepsilon$, I've ...
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1answer
2k views

Relationship between electrical resistivity and density

I just read this answer on EE.SE and that triggered a doubt in me. If I were asked whether there is any relationship between the electrical resistivity and the density of a substance I'd answer ...
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0answers
132 views

Finding the strains from a 0, 90 rosette - Mohr's circle

I have used a strain rosette with two gauges at 0 and 90 degrees to find strain on a beam under force and an trying to plot Mohr's circle for the problem. As the gauges are at right angles finding the ...
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1answer
29 views

will my duraflex seams melt over a fire

Good day ladies and gentlemen, i do realize it may seem like a welding question but i assure you it is physics related. i have built a non pressurized boiler that contains water to be used over an ...
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0answers
378 views

Find the maximum allowable bending moment

A rolled steel universal I-section beam with a serial size of $406\times178$ has a mass of $60$kg/m. What is the maximum safe allowable bending moment this beam can sustain,given that the maximum ...
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1answer
39 views

Would it actually be possible to preserve a snow flake?

In episode one of season 3 of The Big Bang Theory Leonard offers Penny as a gift a snow flake he says he preserved in some kind of resin, having it brought from the North Pole. Is this purely ...
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2answers
118 views

Piezoelectric polarity

After a few days, I cannot find an answer to this question: Besides mechanical stress, is there another way to induce a negative charged surface on quartz? Note: several scholarly articles kept ...
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1answer
44 views

magnetostrictive effect due to earth's magnetic field

is there any magnetic field sensor,which produces stress or strain as output,when that sensor is sensing earth's magnetic field on the surface of earth(0.25 gauss to 0.65 gauss)?or any material/...
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0answers
91 views

coherent grain growth

What is the driving force for growth of coherent precipitates in the matrix? The driving force for growth of incoherent precipitates in the matrix is concentration slope between tiny and large ...
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0answers
59 views

Martensitic transformation in ceramics

What is the specification of Martensite (displacive) transformation in ceramics comparing to yhe one in metals? I just know about Martensite transformation in metals. For example, these ...
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0answers
28 views

Does the surface of austenitic steels have an especially “dynamic” phase somewhere between 100 and 200 Celsius?

There is lots of kitchen lore about pans. One popular concept are the "pores" of a steel pan surface, which are the reason why food sticks to the pan when it's not heated properly. I don't know much ...
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0answers
110 views

How much will a round tube deflect under load? [closed]

I'm trying to determine the materials I need to complete a hobby project, and I'm having trouble estimating how much flex a given steel tube would have under different configurations/loads. My setup ...
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0answers
65 views

Applying Statistical Mechanics to Formulate Corrosion (Rusting)

I wanted to try and take my current knowledge of statistical mechanics (first quarter undergraduate course completed, beginning researcher in far from equilibrium statistical mechanics, basic ...
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1answer
126 views

Drilling a Vault [closed]

Premise I think this is a Physics question, so i thought this would be the right stackexchange website to post my question. If I'm wrong, feel free to move the question in the right website. I'm not ...
3
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1answer
174 views

Theoretical limits to specific strength with hierarchical structures

Specific strength (measured in units of pressure/density or speed$^2$ which in MKS there is a proposal for labelling it as the Yuri (meter/second)$^2$) is defined as tensile strength divided by ...
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2answers
53 views

Are there materials with more than two states that can be used in circuit design? [closed]

Are there atoms or materials that have 3 or more states that can be used in circuit design? Can you provide any examples of such materials, and their possible applications to circuit design? And is ...
5
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1answer
181 views

Superhydrophobic coating and water friction

If you were to apply super-hydrophobic coating to the hull of ships or even submarines, would you get more or less water friction? If the coating completely repels the water you could argue there ...
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1answer
34 views

Stresses in materials depend on co-ordinate system of choice, true or not?

I was studying stresses and strains and my professor told me that they depend on the co-ordinate system we choose to represent, he also said that as we rotate the co-ordinate system, shears that were ...
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1answer
122 views

What is difference between anisotropy and inhomogeinity of this type of composite material?

I am studying some types of composite materials having 2 phases - fibers and matrix. I have some questions and confusions. Any help is appreciated. The composite has fiber along length and I am ...
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2answers
3k views

Melting diamond and cool down as diamond

Is it possible to melt diamond? And if possible while let it cool will it became diamond again?
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4answers
15k views

What common materials absorb most infrared light?

I'm competing in a simple robotics competition where most of the participants use reflected infrared light to detect their opponent. I'd like to make my own robot as difficult to see as possible. What ...
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3answers
822 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 ...
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1answer
49 views

Can I tear apart a pipe with magnetostriction? And how big field should I use?

As I know, with magnetostriction we can "stretch" its unit cell. The stronger is the field, the more it expands the cell. Using alternating current in coils that induce magnetic field we can stretch ...
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17 views
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313 views

Degree of anisotropy of crystal tensors

Does there exist a scalar that can describe how anisotropic the elasticity of a crystal is? What about other tensors such as the permittivity or susceptibility? I found a Wikipedia article that was ...
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2answers
96 views

Why nano indentation is used to test bulk material?

I am curious why nano indentation is used? I can understand when material size goes to micros or below, conventional hardening methods can become difficult to use. However many papers say that ...
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1answer
788 views

Divergence of Cauchy Stress Tensor

On the wikipedia page for the Cauchy Momementum Equation, it's stated that the equation can be written as $$\rho \frac{D\,\textbf{v}}{D\,t} = \nabla \cdot \sigma + \textbf{f}$$ Where $\sigma$ is ...
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1answer
410 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 ...
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0answers
61 views

Why can thermal shocks damage/break materials?

When an object is heated a lot and then brutally cooled down or vice-versa, it can crack or even break spectacularly. What happens inside that makes it do that? Is it only because the hot core swells ...
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2answers
296 views

What are some examples of non-Lambertian light scatters/radiators in everyday life?

What are some examples of non-Lambertian light scatters/radiators in everyday life? How to easily demonstrate their difference from Lambertian ones?
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1answer
310 views

Is there a difference between spring fatigue and plastic deformation in springs?

Is there a difference between spring fatigue and plastic deformation in springs? Plastic deformation means permanent deformation in springs caused due to stretching in springs.
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2answers
5k views

Is ice a type of glass?

It's kind of a tricky concept I assume, on one side you got those neat shared vertices of SiO2, on the other (water) you don't really have shared vertices, only kinda (but they still want to align ...
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0answers
159 views

Tensorial version of Hooke's law

It is well known that $${\boldsymbol F} = k {\boldsymbol x}$$ for isotropic media. Also, according to Wikipedia $$F_k = k_{jk} x_j$$ for some elastic tensor $k_{jk}$. I'm a bit confused as to how ...
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1answer
215 views

Why do we have Indirect bandgap semiconductor?

If the energy of an electron is proportional to square of the momentum k, how come we have a Indirect Bandgap material in which the minimum of the energy in conduction band is not at k not zero. P.S. ...
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1answer
48 views

How can I get some conductive polymer (silicone like), with 1 Ohm/cm resistance? [closed]

I'm looking for a silicone-like (flexible, stretchable) conductive polymer with 1 ohm/cm resistance. Does anyone happen to know where/how can I acquire some? Thank you very much for your time.
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1answer
146 views

Martian space elevator from the vulcano Olympus Mon to the moon Phobos?

In my fascinating imagination, I am seeing a space elevator from the vulcano Olympus Mon to the moon Phobos. Phobos also seems to keep spaceships - while a smaller shuttle attaches itself to the ...
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2answers
157 views

Software for analysing SEM or TEM images

I am looking for a software to analyse SEM and TEM images of some PLD experiments because I want to characterize the samples, like calculate the concentration of nanoparticles, size, and do some ...
2
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1answer
173 views

Cold welding of a metallic surface

I have heard of cold welding, it's said that it's only possible if the surface is very clean. Can cold welding be accomplished by shearing a metal object and then immediately touching the newly ...
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7answers
664 views

Is it possible to cut harder material with a less hard material?

Is it possible to cut harder material with a less hard material - for example cut a steel rod with iron blade ?
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0answers
15 views

What are the factors affecting transparency and color of a substance [duplicate]

What is the reason behind visual properties like color and transparency of different substances? I have always heard that the structure of the substance is responsible for these properties. I always ...
0
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1answer
21 views

Material for moisture moderation

Do you know of any material that can moderate the level of moisture of its local environment? Example: if the desired moisture level is 30% and the local environment of the material is at 6% the ...
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0answers
30 views

Material that can provide soft flexibility, while maintaining conduction “accuracy”

I hope material search may be valid here. Is there a material that can be shaped as a few millimeters thick sheet, that can be placed on top a touch surface (e.g. iOS/Android tablet, Wacom drawing ...
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2answers
744 views

Why is steel-reinforced concrete stronger than ordinary concrete?

Is it only because steel has higher elasticity? What other factors are involved?
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0answers
88 views

What is the yield strength of a bar of different cross sections?

Will the yield strength of the combination will be same as that of the rod of uniform cross section?
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2answers
251 views

Does induced current affect the permeability of a material?

For electromagnetic wave propagation, we can typically characterize a medium by conductivity $\sigma$, permeability $\mu$, and permittivity $\epsilon$. Consider if this material had current passing ...