Questions tagged [material-science]
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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What makes quartz oscillators vibrate?
I understand that the principle behind it is piezoelectricity and electrostriction (inverse piezoelectricity), but how does one make the crystal vibrate?
The only thing I can think of is using an ...
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What solid elements, if formed into their thinnest possible 'sheet', would be translucent?
Would this have to be experimentally done or is there some manner to estimate translucency based on molecular properties?
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How to calculate thin film interference when the incident medium is absorbing?
Edit: I found a text that mentions that when the incident medium is absorbing, the usual equations for interference don't apply, so I have refined my question in the title.
I have been working on ...
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Can Thermal cameras see through walls?
I saw this cod black ops 4 cod is based on realistic gameplay, so i am curious if thermal cameras really can do that? i think this may be a possibility if the sensors are highly sensitive and can ...
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Spring Constant Dependence on Contact Area
I'm actually modeling a contact situation between an elastic cuboid (in reality it is an elastomer) and a non elastic sphere ($c_c\ll c_s$). The spring constant $c$ is defined with the young's modulus ...
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What is glass: amorphous solid or supercooled liquid?
I have read glass is amorphous solid and also supercooled liquid. I know that all solids are frozen liquids. But is it fair to say that everything which is an amorphous solid is also a supercooled ...
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What is the difference between grain boundaries and dislocations?
Specifically I'm interested in how the difference relates to plastic deformation.
To my understanding, a dislocation is a non-uniform part of the crystal lattice (basically where the crystal isn't ...
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How does thermal insulation work at the molecular level?
I don't understand why insulation works. For example, imagine we have the same thickness of wood, fiberglass and aerogel. Each insulates to a different degree, the more rarified material, the greater ...
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Metamaterial : Snell's law and Fermat principle
How do we deduce Snell's law using Fermat's principal in case of metamaterials? Metamaterials have negative refractive index. This makes the refracted ray of light bend on same side of normal as ...
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What is so special about calcite that it has double refraction?
In this video is explained how the double refraction occurs. But it explains that if the ordinairy ray is horizontal and the extraordinairy is vertical that the first one gets less delayed than the ...
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Mechanical Property Responsible for Folding
I was wondering on which property does a material's tendency to fold depends upon.
When we push a metal plate, it seems to move forward. However a rug would start to fold and form crests. A piece of ...
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Cutting silicon samples with plastic thin films
I'm measuring thicknesses of ~15 μm nickel thin films electroplated on a silicon substrate. I only have access to a SEM for this task. I need to cut the samples to get a side view of the film. However,...
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How does an infinitely hard tip scratch an amorphous brittle material when it slides along it?
I know infinitely hard materials don't actually exist but sometimes the tip is so much harder than the substance it's scratching that it can be treated like one. Suppose a sharp diamond tip is made to ...
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Is stiffness of a beam the product of Young's modulus and second moment of area?
Is stiffness of a beam the product of Young's modulus and second moment of area? I read online that stiffness of a beam is function of the product of young's modulus and second moment of area. I ...
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Is this a fundamentally relativistic phenomenon?
This question was inspired by some silliness in other threads but is independent of that silliness.
Say that a train car sitting on a track is accelerated uniformly along its length if each point on ...
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Why is metal stiffer at lower temperatures?
Each morning I cycle to school and lock my bike with a thick steel wire (about 8 mm thick). I noticed that it's much harder to change the shape of the wire in the morning when it's much colder than ...
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How is spring steel so hard?
The mechanical properties of a steel object are influenced by the metal composition, the manufacturing process, and the final heat treatment of the object.
Spring steel is a steel that was heat ...
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Why does adding thorium to a TIG welding electrode improve the arc?
Why does adding thorium to a TIG welding electrode improve the arc? What are the physics behind this and other tungsten alloys used for improving TIG electrodes?
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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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What is the meaning of $\%E$ on a graph?
I'm reading the book The New Science of Strong Materials by J.E. Gordon. He writes
when we plotted (...) breaking strain, against thickness, we found it did not matter what the whiskers were made ...
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Where will a board break when weight is added to the end?
If you have a board, say a standard 2x4 of finite length, where one end is fixed in a cement wall and the other end is free, and you begin adding weight to the free end until it breaks, where will the ...
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Pressure applied to flat plate
I have a question about the pressure placed on a plate of material X, how the force is distributed and what would be the material property that would determine its failure.
To simplify things "...
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Abacus about the thermal expansion of copper
I am currently working on the measurement of the coefficient of thermal expansion of copper. In order to compare my experimental results with theory or experiments made by others, I am looking for ...
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Computational Science involve programming? [closed]
I read what is computational science in Wikipedia but the explanation and understanding are not very clear.
So, I could you please give a simple example computational science project and what all ...
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What will the strength of a sintered steel piece be compared with a cast piece?
By sintering here, I mean specifically deposition laser sintering, i.e., put down a patch of steel powder, zap it with a laser so that it liquifies at least partially, lay down a new patch, laser, ...
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How does restoring shear forces arise (in elastic conditions)? Do they arise from central forces or not?
When you apply a shear force onto a solid piece of material (say a block on a surface or a cantilever
beam with a load) that creates shear stress in the elastic regime, there is a restoring force that ...
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First mode of vibration for a glass window
How to calculate the first mode of vibration for a glass window?
I have a window of the size 57 cm by 106 cm and 4 mm of width. I hear the loud noise from it on about 166 Hz and want to realize if it ...
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Shape of fastest spinning rod
A one-meter steel rod of variable thickness is attached at one end to a spinning hub. The cross-sectional area of the rod is a function $f(x)$ of the distance $x$ in meters from the hub, x ranging ...
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How do we justify that potential energy in a spring is Galilean invariant (to the extent that Newtonian mechanics holds)?
A spring can store elastic potential energy by elastically deforming and moving its atoms out of their minima potentials. The atoms themselves can be modeled as balls connected by Hooke-like springs ...
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Why a rotating body ruptures at a transverse velocity equal to the speed of sound in the body?
In this article about Ehrenfest's paradox, an introductory remark on classical rigidity is made:
Any rigid object made from real materials that is rotating with a transverse velocity close to the ...
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Can electron confinement systems display hyperfine transitions?
Just as Quantum dots can display the energy transitions characteristics of electron in a conventional hydrogenic atom to give emission tunability, can it and other similar electron confinement system ...
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How does a materials modulus of elasticity (proportional zone ratio) relate to crystal defects?
I'm studying biomedical engineering and I'm about to take "Biomaterials" (basically materials science applied to medicine) final exam. In one recorded class, the professor mentions the ...
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Finding the pressure difference inside a volume due to the expansion of its outer layer
FORNOTE: Hey all :) this is my first time posting and I apologise if I have written a block I wanted to be as precise with my question and reasoning as possible, also the question is summarised in the ...
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Conservation of Angular Momentum and Paramagnetism
You can think about a paramagnetic material as being comprised of a bunch of quantum mechanical spins aligned in random directions. When an external magnetic field is applied, a fraction of the spins ...
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Theoretical justification for the range of validity of the approximation $R(T)\approx R(T_0)[1+\alpha (T-T_0)]$
In the experiment for calibrating a platinum resistance thermometer, we are always approximating the resistance of the platinum thermometer by $$R(T) \approx R_0 (1+\alpha T),$$ taking the reference ...
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Deformation without stress?
Elastic bodies are submit to stress whenever they are deformed. This eventually lead to break them.
However, let's consider a rope. If i stretch it, it is submit to stress and will eventually reach ...
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How do materials absorb light
I'm curious how light is absorbed in materials. From what I understand, when an electron absorbs a photon, it gets excited to an energy level that is higher than the level it's in and the energy ...
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Is it possible that the speed of sound in some strange quantum material is faster than the speed of light in vacuum [closed]
If we believe the spacetime structure(including the limit of speed) could emerge from some vacuum structure(such as string-net condensation),then, is it possible that the speed of mode of excitation ...
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Tearing paper by creasing/folding
Why does folding/creasing loosen the fibre-fibre bonding in paper?
Creasing makes tearing paper easier because it weakens the fibre-fibre bonds or makes the strong fibres easier to tear, it is said. ...
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How are atoms supported on each other in a material?
Suppose we have a ball made up of iron. There are a "lot" of atoms in the ball.
My question is "how" are the atoms supported on top of each other?
And, is it due to the repulsion of electrons the ...
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Why is the mechanical energy lost whenever an object undergoes plastic deformation?
I have read here that "Mechanical energy is lost whenever an object undergoes plastic deformation."
Why is that? I mean the object would be changing its shape, and while it's changing its shape it ...
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Do materials gain compressive or tensile strength if compressed?
If I take a block of play-dough and squish it down, it becomes harder to pull apart and push together.
Does this same phenomena hold for "real world" materials? If I take a block of steel and ...
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Difference between bending elasticity and Stretching elasticity in complex solids
In a solid, elasticity is described by the Young modulus E.
Let us consider a thin sheet of material of thickness h.
The bending rigidity is usually Eh³.
I wanted to know if they are "abnormal" ...
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angles in mud flat cracks
This image of a cracked mud flat from
https://www.msichicago.org/explore/whats-here/exhibits/numbers-in-nature/the-patterns/voronoi-pattern/
shows that when three cracks meet at a vertex they (tend to)...
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Strain-Energy and Deflection function
I am trying to understand how to derive the mechanical strain energy in an Euler-Bernoulli beam fixed between two torsional springs as shown in this paper: http://iopscience.iop.org/article/10.1088/...
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Why would a suddenly applied force have more impact than the same force being applied over time?
I'm a fan of computer keyboards, and I was thinking about the durability of electrical contacts that lay below the keys on certain kinds of keyboards, such as this one.
I tried to wonder how many ...
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Why does a rotating flexible disk have wave shape?
I found a video on which they shatter CD with a high RPM tool. Before the CD shatters it has a wavy shape, so I guess an axial force shatters the CD instead of a radial force, probably some kind of ...
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Definition of granular material
I am doing a project on some properties of granular materials. I might have to face people who ask the definition of granular material. How can we define granular materials? One answer is "it is sand-...
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How does the rupture limit of a cable depend on its length and cross-sectional area? [closed]
So I was doing my physics homework and found myself stuck on this question:
A new composite material for the carrying cable of a lift should be used. In a test series in the laboratory, for a $2.5$ ...
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How do magnetic cores (ferrites) guide magnetic field?
As far as I know, magnetic materials have magnetic dipole moments which align when they are under influence of the outside magnetic field.
Basically they increase the magnetic field strength. But ...
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