Questions tagged [materials]

Use for questions about designing, manufacturing or synthesizing engineered materials or about the properties of specific materials. Questions concerning common construction materials, such as wood, steel or masonry do not need to use this tag; use the more specific tag instead.

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Static charge, PVC pipe and water

I know it's possible for a PVC pipe to develop a staic charge due to fluids flowing through them. This is a twist on that idea. Can a sealed length of pvc (say 3.5 feet in length) - tethered below ...
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25 views

Factors for Rope Elasticity

What factors, given the same material, change the elasticity of a rope? For instance, nylon rope can be configured to stretch elastically anywhere between 5% and 30% under a specific load. This is ...
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What is a common polarizing 50/50 beam splitter cube coating

I am having problems locating references of the typical thickness and material of the coating along the hypotenuse side of 50/50 polarizing beam splitter cube. Does anyone know what these coatings ...
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1answer
23 views

Adhesion of Super Glue (containing ethyl cyanoacrylate) and PVDF (polyvinylidene fluoride) film

Would it be considered safe to use super glue, which contains ethyl cyanoacrylate, to attach a PVDF film to a metal alloy? It says super glue is not recommended for polyethylene or polypropylene. ...
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3answers
58 views

Will electroplating a ventilated brake rotor with copper improve its cooling capacity and maximum its lifespan?

Since copper is excellent at dissipating heat and does not rust, I am surprised that brake manufacturers do not electroplate cast iron/steel brake rotors with a thin layer of copper (~.5mm). There are ...
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2answers
52 views

Why are moulds sometimes dimensionally larger than the metal components they make?

I have this question and I can't seem to find any sources which I can used to determine a potential answer.
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22 views

What is the smallest grain size achievable using mechanical methods?

What is the smallest grain size achievable (both theoretical and practical) using mechanical methods to crush a fracturable mineral composed primarily of a single molecular species? Example minerals ...
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10 views

Viscoplastic model of solder alloys

I have found some data of viscoplastic Anand model for the SAC305 solder joint of electronic devices in the literature. Does this data depend on the thickness, length and width of the joint? I mean ...
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3answers
49 views

Calculate area of mesh?

I have expanded steel mesh that I use to make garden cages: I would like to know how much sunlight the mesh blocks. I think I need to calculate the area that the mesh takes up (per square inch) and ...
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3answers
177 views

Jet Boat Engine Part Identification

If anyone can provide me information about this part right here, please tell me.
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2answers
64 views

Material that holds shape when stretched

I'm looking for a lightweight material that will hold its shape when stretched out. Something like a rubber band that doesn't snap back. So it starts out small, but once it's stretched it stays large. ...
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0answers
24 views

Rust formation on Cold rolled carbon steel(SPC 270D)

We are using Cold rolled Carbon steel(SPC 270)grade. We have observed rust formation due to exposure to air(8-12hrs). The rust analysis resulted 1.6% chlorine whereas allowable limin is <0.01%. Air ...
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3answers
71 views

Tube Strength vs Pipe Strength

I've been going down the rabbit hole as far for pipe vs tube and have ran into the same statement from co-workers and on the internet. That statement is "TUBE IS STRONGER THAN PIPE" https://www....
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2answers
174 views

How to make sure the material is titanium?

I am looking for non-destructible way which can be performed in home conditions to tell if the material is titanium (in my case it is a mug). Advices like "grind it" or "use electronic microscope" ...
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1answer
25 views

What are equations related to the compaction of composite metal powders?

Say I am trying to create a metal composite and have a mixture of 3 different metal powders each with varying weight %'s. I'm going to compact them into the shape of a ring by applying a force P. The ...
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3answers
36 views

Thermal Non-Insulators?

I need a clear material that will allow sun in but won't insulate heat. Sun sun rays get in but doesn't trap heat. Any ideas?
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2answers
40 views

What is the meaning of line and points in the schematic of a polymer

In the engineering material book. It shows the following figure The following is the text to depict the picture "The origin of rubber elasticity is more difficult to picture than that of a crystal or ...
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1answer
73 views

Thermal expansion of a hole in a plate with a temperature gradient

I have a rectangular metal plate with a hole in it (with diameter of 300 mm). The plate has a temperature gradient going from one of its short sides to the other, I can measure the temperature ...
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0answers
24 views

Will a video projector submerged in mineral oil still work?

I’ve seen folks submerge computers in mineral oil to cool them- but would doing the same to a video projector profoundly throw off its internal optical aspects? I’m considering one of those small “...
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21 views

Equilibrium concentration of point defects in solids at sufficiently elevated temperature

Equilibrium concentration of point defects in solids is defined as $\chi=\exp(\frac{\Delta s}{k_B})\exp(\frac{-\Delta h}{k_BT})$. At high temperatures, may be even higher than melting temperature of ...
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11 views

What is the compressive strength of carbon nanotube reinforced polymer?

What is the range of compressive strength of carbon nanotube reinforced polymers? Although CNT's themselves have phenomenal (oriented) compressive strength, and one can find references to that, CNRP'...
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2answers
50 views

What are the design principles for risers in sand casting?

Risers are added reservoirs used to feed liquid metal to solidifying casting. In the case of alloys that shrink during solidification (this is not the case of all alloys), one uses such reservoirs to ...
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2answers
42 views

Is a 1/8" AR400F steel plate strong enough, for 4,000 lbs?

I have a Ford F350 cab & chassis and a gooseneck trailer. For the gooseneck hitch I want to use a steel plate. The steel plate will be BOLTED to the frame, above the rear axle And the gooseneck ...
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0answers
29 views

Relation between burgers vector, slip plane, dislocation motion direction and dislocation line

I am really confused about the relation of this 4 entities. I know that the dislocation line is perpendicular to the burgers vector in an edge dislocation and parallel to the b vector in a screw ...
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1answer
85 views

How will using desert sand instead of concrete sand affect my concrete recipe?

I've read that desert sand is too round for concrete mixes. But, I'm not building a dam, I'm building a 3 foot landscaping wall. I'm interested in using desert sand for the color, so this is an ...
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1answer
68 views

Compressional Strain Definition

Strain in the x and y directions are defined by the following equations: $ε_x=\frac{du}{dx}+\frac{1}{2}[(\frac{du}{dx})^2 + (\frac{du}{dy})^2]$ $ε_y=\frac{dv}{dx}+\frac{1}{2}[(\frac{dv}{dx})^2 + (\...
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1answer
34 views

Help with determining the dimension change in the xyz direction of a component under a load?

I'm stuck on this question. I got the first part right which is to work out the dimension change in the x direction but I got the y and z directions wrong. I had to submit this online and it doesn't ...
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18 views

Phase prediction by cct diagram

Can someone please help in finding out the phase proportion of each phase w.r.t time , cooling rate and temperature by using (mathematical model to predict phases from given cct diagram) Leblond ...
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0answers
15 views

What's the methodology for adequate tetrahedralisation?

I'm running a linear elastic solver generating the tetrahedron's using tetGen. It's not clear to me though how one defines what's an acceptable tetra density that provides sufficient accuracy. You ...
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1answer
77 views

Which way of joining is stronger?

I have to build a box to extend the length of a projector bracket: The projector bracket weighs 7kg and has an arm of about 500mm. The projector weighs another 5kg. The box has a depth of 140mm. ...
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0answers
17 views

Ion exchange membrane that is dimensionally stable in organic solvents

For an electrochemical flow cell stack employed in electrosynthesis, I require an proton exchange membrane (PEM) in order to enable "divided cell" electrolysis mode. The Nafion proton exchange ...
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2answers
63 views

Could pre-stressed graphene be used to reinforce granite block construction?

I am curious whether this will become an option, especially for longer lasting structures. Could pre-stressed graphene or another high tensile strength material by used to reinforce granite block ...
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1answer
47 views

Stress strain curve [duplicate]

According to uniaxial stress strain curve, specimen fails at a certain stress value since necking begins. My question is that, same stress value appears before necking especially around yield point ...
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0answers
30 views

Is acrylic OK for children's toys under EU regulations?

I am developing a toy for 2-6-year old children with parts in acrylic ( Poly(methyl methacrylate)). I searched Toy Safety Directive 2009/48/EC and Regulation 1907/2006 REACH for mentions of perspex or ...
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How to find phase proportion at equilibrium - from iron-carbon diagram - Leblond

{Equilibrium proportion P, this is the proportion which is reached at a constant temperature after an infinitely long time:P is also the austenite proportion in the case of extremely slow heating. It ...
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3answers
241 views

Strength vs. Hardness vs. Toughness

for this question: "What is the difference between strength, hardness and toughness in materials?" i have searched and have found these following definitions Strength refers to resistance to ...
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1answer
39 views

Screw Dislocation and Edge dislocation

If in both cases if there is an application of Shear Stress then why do we have Screw dislocation in one case and Edge dislocation on the other?
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1answer
29 views

Which material index should be maximized for a component in a Car's manual type HVAC?

I was doing a case study on the plastic used in cars for controlling the AC in a manual type system which actually snapped in mine it just rotates according to the knob position in the dashboard, ...
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1answer
16 views

Finding Stress Concentration Factor when (D/d) ratio is not on a table?

So we have this homework problem, it is a rectangular filleted bar and we have to find the minimum thickness. I go and calculated the ratios but here's the problem: (D/d) = 1.375. What may the problem ...
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What bending test and torsion test standard are recommend for a surfboard?

I wish to find a bending and torsion test standard for a surfboard (non-prismatic) that is roughly 2000mm long. The closest I've found for bending test is probably those ones that are designed for ...
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18 views

How can I increase the strength of this clutch without shearing my bushings?

Here's the setup: (C) is a clutch. Beyond (C) is the source of torque. The belt (D) transfers the motion from the clutch to the sprocket (B). (B) then transfers the motion to (A) by way of 9 ...
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30 views

Why the Tensile modulus is always larger than Tensile strength?

I can't figure out this huge difference in values between these two mechanical material properties. When its refer to flexural strength and modulus there's a difference in value (if the material is ...
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2answers
47 views

Can a simple application of two forces have two different outcomes on a rigid body?

[Summary: If two forces are such that the component of one of these forces forms a couple with the other, than which of the two cases (obtaining resultant via adding forces or obtaining moment and a ...
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2answers
45 views

Material for car mounted fire extinguisher bracket

Don't try this at home. I am taking personal responsibility for what happens in my car. Hi all, I recently purchased a fire extinguisher for my car (it weighs 1.5 lbs or 0.68 kg). I browsed the ...
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1answer
50 views

Why do people build the core of a sandwich structure using compsite

Usually I see composite as a laminate wrapped around the core of a sandwich structure. Usually in loading such as bending the bending stress is the highest furthest away from the neutral axis, while ...
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1answer
48 views

Force required to deform sheet metal

Hi all. I am building a machine to deform sheet metal into corrugations. I have attached an image that I got off a presentation from MIT's website. In the example, they provide a formula for the ...
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1answer
45 views

Which is more important XY plane thermal conductivity or z direction thermal conductivity?

Im seeking an alternative to thermal grease/ pastes. I was researching graphite pads when I stumbled across the soft PGS line from Panasonic. I need to choose a suitable thermal interface material ...
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2answers
40 views

Why does aluminum clad steel wire have high corrosion resistance?

Why do aluminum clad steel wires have high corrosion resistance despite being two dissimilar metals? Does the aluminum act as a protective & sacrificial layer similar to zinc in galvanization or ...
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1answer
53 views

Does tunnel lining made of cast iron tubings actually accept all the mechanical loads?

Here goes a recently opened underground railway station in Moscow, Russian Federation (image is from here) On the left is an undecorated (just painted and it will likely remain this way) tunnel wall. ...
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1answer
61 views

Recommendations on a rigid connection between materials

I am trying to construct a torsion pendulum/balance for a physics experiment but the research papers are always missing specifics on how the certain connections are made. I am looking for ...