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.

Filter by
Sorted by
Tagged with
0
votes
1answer
24 views

Is there a relationship between depth/diameter/etc… of meteoric craters and the strength (eg:compressive strength) of the target material (sand…)?

So I am trying to write a high school research paper (3700 words) on the topic above. I am not sure if there is such a relationship, but I think intuitively we can agree that different materials will ...
0
votes
1answer
54 views

What is a material that allows air to pass but not water vapor?

What are some materials that allow air to pass but not, or to a lesser extent, water vapor? Here are two materials I am aware of: Teflon is a material that allows water vapor to pass, but not air. ...
0
votes
0answers
26 views

“Naturally, a low stacking fault energy also favours annealing twins since growth accidents are easier to tolerate.” [on hold]

What is the meaning the the aforesaid statement.I know very well that stacking faults play a role in annealing twins particularly in the context of copper and aluminium.Please explain the meaning of ...
1
vote
2answers
70 views

What happened to the projectile in Hypervelocity Impact tests?

I recently saw a tweet about Hypervelocity Impact Sample and someone ask how is it possible to shoot a projectile at that speed and what happened to the used projectile when hitting the shield. I ...
0
votes
1answer
23 views

Carefully attaching Pt-wire to mild/carbon steel surface

Problem: I have a near 100% Pt wire (25 AWG / D ≈ 0.45mm) that I would like to attatch to a cold rolled steel (E235 / EN 1.0308) surface. Assume this surface is flat. Goal: Keep wire attached to ...
0
votes
2answers
75 views

What should be the material and thickness of front pillars to stop car (~1,847kg and ~262 km/h) without killing the driver?

"Tesla Model 3 owner died in a tragic accident with a semi truck. The Model 3 went under the truck’s trailer resulting “in the roof being sheared off as it passed underneath,” which is known as a “...
3
votes
0answers
19 views

Will a cyclic heat load transform my martensitic steel? How fast?

I have a plunger - that I'm using for glass forming - made out of a martensitic steel. Glass is at 1000°C and since martensite is a metastable phase, should I expect the properties of my plunger to ...
0
votes
0answers
22 views

How to write the equilibrium stress equations for a hollow, rectangular beam?

I have a system consisting of a hollow, rectangular cantilever beam (pictured below). I'd like to write the equilibrium stress equations à la the Cauchy Stress notation. How do I account for the ...
0
votes
0answers
9 views

Heat press of vinyl on 100% polyester fabric

I want to customise a piece of fabric that is 100% polyester (exclusive of decorations, wash at 30º) with vinyl. My idea is to use a vinyl cutter (such as Silver Bullet) to cut a pattern on the sheet, ...
0
votes
1answer
28 views

Material for filling small air leaks

Often beeswax is used to seal small air leaks on some musical instruments. One of the disadvantages of beeswax is that it has a melting point of around 140 degrees Fahrenheit and can therefore flow to ...
0
votes
0answers
12 views

Anyone facing issues with a compact roller press machine?

I am currently facing a problem with the machine above. When I try to compress something using the roller machine, sometimes my sample will have "scratch" marks after coming out. There are no foreign ...
1
vote
0answers
16 views

“bubbles” forming after heating my Thin film transistors

I am fabricating Bottom gate Thin-film-Transistors. The Gate is 60nm Molibdenum. The dielectric structure changes with the table below. The temperature represent the annealing temperature after ...
1
vote
1answer
55 views

Material to absorb very low frequency radio

Is there any material that will absorb very low frequency radio light? I know that stealth aircraft use radar absorbant materials in their design that absorb radio light best at certain frequencies, ...
1
vote
0answers
21 views

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 ...
0
votes
0answers
30 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 ...
1
vote
0answers
20 views

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 ...
1
vote
1answer
31 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. ...
1
vote
3answers
71 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 ...
3
votes
2answers
57 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.
1
vote
0answers
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 ...
0
votes
0answers
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 ...
3
votes
3answers
50 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 ...
2
votes
3answers
189 views

Jet Boat Engine Part Identification

If anyone can provide me information about this part right here, please tell me.
2
votes
2answers
66 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. ...
1
vote
0answers
27 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 ...
1
vote
3answers
86 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....
1
vote
2answers
175 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" ...
0
votes
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 ...
0
votes
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?
2
votes
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 ...
2
votes
1answer
76 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 ...
0
votes
0answers
27 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 “...
0
votes
0answers
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 ...
0
votes
0answers
12 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'...
1
vote
2answers
65 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 ...
0
votes
2answers
44 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 ...
1
vote
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 ...
1
vote
1answer
87 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 ...
1
vote
1answer
92 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 + (\...
0
votes
1answer
35 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 ...
0
votes
0answers
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 ...
0
votes
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 ...
2
votes
1answer
78 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. ...
1
vote
0answers
18 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 ...
0
votes
2answers
68 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 ...
2
votes
1answer
50 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 ...
0
votes
0answers
40 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 ...
0
votes
0answers
19 views

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 ...
1
vote
3answers
377 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 ...
0
votes
1answer
52 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?