[remotemass (OP)]

What is the smallest laser able to melt iron made by nanotechnology?

It seems an interesting example application of nanotechnology to hold in mind and to think about and for that matter I am willing to know more about implementing such nanomachinery. The smallest laser able to melt iron would be a device that can generate a high-intensity beam of light at a wavelength that can be absorbed by iron and cause it to reach its melting point, which is about 1538 degrees Celsius.

One possible way to create such a device is to use selective laser melting (SLM), which is a technique that can produce near-full density metallic objects by completely melting powder particles with a laser beam. SLM can be used to create complex shapes and structures with high precision and accuracy, and it has various applications in fields such as aerospace, automotive, biomedical, and more.

However, SLM is not a simple process, and it involves many challenges and parameters that need to be optimized.

For example:

1)  The materials properties, such as composition, size, shape, and distribution, affect the melting behavior, density, porosity, and mechanical properties of it.

2)  The laser parameters, such as power, speed, spot size, scanning strategy, and hatch distance, affect the thermal gradients, residual stresses, microstructure, and surface quality of it.

3)  The process environment, such as temperature, pressure, atmosphere, and shielding gas, affect the oxidation, evaporation, spattering, and contamination of it. Creating the smallest laser able to melt iron would require careful selection and control of these factors and I am looking for any information about the exact size or shape of such a device.

I hope to learn more about the smallest laser able to melt iron.

- remotemass

[alancalverd]

Why small? And which part of the equipment do you want to be small? Indeed, why a laser? You can melt iron with a mirror on a sunny day - you just need a very good mirror!

[remotemass (OP)]

Smallest as in recordist achievement of all time. I am also interested in other smallest machines and in nanotechology tools and creations in general, namely in the smallest specific engines like very specific electric motors. But the question is about lasers able to melt iron. If they can melt iron they can certainly be used for many other things and is interesting to study the teoretical limits of their sizes, I think. Lasers usually have complex lenses and optical mechanisms and materials science keeps improving the manufacture of these optical devices so thinking about how small and potent they can be may be interesting to people and to many scientists.

- remotemass

[Bored chemist]

You forgot to answer Alan's question.
What do you mean by smallest?
Shortest?
Narrowest?
Lightest?
Lowest power?
(Maybe even cheapest)?
Also, in the presence of air, iron is capable of melting itself.

[Petrochemicals]

lazers can be very very small, perhaps one photons width.

https://cutlasercut.com/drawing-resources/expert-tips/laser-kerf/#:~:text=The%20laser%20burns%20away%20a,experienced%20when%20cutting%20thicker%20foams.

[evan_au]

Provided you thermally isolate the iron particles in a vacuum, and surround it by mirrors to keep most of the radiated heat in, you shouldn't need a very big laser to melt it.

Particles of iron can also be very small. The iron particles which form "seeds" for carbon nanotubes are only nanometers across. The main challenge here is how to focus a significant amount of optical power on a target which is smaller than a wavelength.

[alancalverd]

Use an x-ray laser. The laser element can be tiny even if it needs a few megawatts to turn on.

OK, I'm "ignoring the weight of the elephant" here (like how do you focus the x-rays?) but we're talking physics, not engineering, so I'd specify an unobtanium lens in an adamantium holder, and leave it to the workshop to source the materials.

[Bored chemist]

lazers

Light amplification by Zimulated emission of radiation.