Questions tagged [material-science]
126 questions
17
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2 answers
Why doesn't epoxy stick to silicone?
Why doesn't epoxy stick to silicone? Is there a type of epoxy that does?
Geremia
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11
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4 answers
Why are most jigsaw blades designed to cut on the up stroke and have teeth that point towards the shank?
Why are most jigsaw blades designed to cut on the up stroke with teeth that point towards the shank? Why are reverse teeth jigsaw blades less popular?
Adam
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4
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How to judge the character and sign of a dislocation?
I do understand that $ \mathbf b||\mathbf t$ for screw dislocation but I am unable to judge the sign of the dislocation. Again if $\mathbf b \perp \mathbf t$ how do I judge its sign? Any formula which explains the sign and magnitude (to some…
user586228
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4
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2 answers
Why does corrosion take place at certain stressed regions?
Why does certain parts of metal show more corrosion at the place where there is high dislocation density in comparison to the place where the dislocation density is less? I do sincerely feel that this is particularly because of the fact that the…
user586228
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4
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1 answer
How is linear motion achieved in this automatic blackboard eraser?
In the animation shown below what can be the mechanism used for this purpose? I know it can be achieved by using rack and pnion gear arrangement. But how are this set up arranged in classroom environment, I have no little idea. Please help me about…
Satya
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4
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4 answers
How does a pressure vessel fail when the interal pressure exceeds the yield stress of the material?
When we design a pipe or pressure vessel, we look at hoop stress and longitudinal stress and then look at the material properties. We assume that the material reacts to the load as a solid. However This answer and comments claim:
Wall thickness…
mart
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3
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Plastic hardness after machining vs molding
Should there be any difference in the hardness of a plastic material that is machined vs one that is pressed from a mold?
This question is in specific reference to vinyl record production where records pressed/stamped from molds are seen to be more…
Lukas L
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3
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How do I EXACTLY calculate the k-factor for metal bending?
Introduction
I've recently started to work with metals and the process of bending them. There is a lot more math involved than I initially thought. All the break press operators just have a standardized list of k-factors that they either use or…
Kapfy
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3
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2 answers
Heat Deflection VS Coefficient of Thermal Expansion?
I was looking at a spec sheet for a photopolymer and saw these two different subsections under the "Thermal" section. I tried Googling around as I usually do, but no site could give me the clear difference between the two and some simply defined the…
Sophia
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3
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2 answers
Why would the flexural modulus be different than the elastic modulus?
I'm reading the Wikipedia page on flexural modulus. It is said:
Ideally, flexural or bending modulus of elasticity is equivalent to the tensile modulus (Young's modulus) or compressive modulus of elasticity. In reality, these values may be…
S. Rotos
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4 answers
What is the significance of brittle materials and why do we use them?
What is the significance of brittle materials and why do we use them?
As you can see in the stress-strain curve, brittle materials have extremely low plasticity, in which cracks can initiate without plastic deformation and can soon evolve into…
Ibrahim Omer
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2
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3 answers
Difference between fast or slow rising force on materials' breaking strength
Assume that force is applied to a material like a rope, steel cable or a beam until it tears apart.
Does it make any difference for the breaking point if the force rises slowly or really fast?
ja b
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2
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1 answer
Mirror specification used in Solar Fresnel Collector systems
Im designing a Linear Fresnel collector system, and wanted to know what type of mirrors would be suitable for use as the reflectors. Thickness, type, coating etc. I couldnt find a manufacturer of ''tempered mirrors'' where I live. I need it to be…
afterburner77
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2
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1 answer
How do the constraints imposed on a material increase the stiffness?
As the title of this post says, how do the contraints increase the stiffness. For example, I was doing an exercise where I had to calculate the deflection on a rubber block with and without deflection and they mentioned that "the constraint…
iZxCV
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2
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Is there a name for a process of constructing gradient/smoothly distributed material density?
Are there conventional processes by which one can construct a material that gradually transitions from one alloy or molecular density to another? For instance if I wanted a material that gradually transitioned from steel to cast iron or from rubber…
PhiEarl
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