I had this effectively a shower thought idea - why don’t we have ceramic 3d printing?
Let me clarify - before posting, I looked it up, and I could not find exactly what I was looking for. There are already commercial offereings for Clay 3D printing, but that is not forming the ceramic in situ, we are depositing what is effectively ceramic in a solvent, and drying it. What I was thinking was making the ceramic on site.
Here is a example setup
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Imagine a regular polymer 3D printing setup
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imagine instead of filament, we have a tank of Ca(OH)2 (calcium hydroxide, or slaked lime) (not necessarily just this, but for example, consider this combination)
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imagine we instead of droping a full thread like layer of semi-solid polymer, we form a trail of really tiny water drops
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we sprinkle in Ca(OH)2 onto the drops (or this step can be skipped if we can pre mix it with water, and then somehow figure how to deposit really tiny drops of what is effectively a very strong base
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now we let CO2 in, and form CaCO3
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deposit a layer to fill voids in this layer (we dropped a non continous strings of drops earlier)
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evaporate remainning water
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repeat this step until this layer is complete.
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repeat process for next layer
Now I can think of many problems here
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how to handle very strong base - maybe a tip of refractory alloys, or something like Inconnel (or Ni Cr alloys in general), or ceramic (maybe alumina) coated metal (probably cheapest, but hard to make)
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how to control solidification - we are effectively doing a solidification reaction, and growth of crystal would largely be dependant on the crystal facettes, and we would not be able to have any sharp angles. Also, we would not be able to have a very small width with this.
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surface tension of water will not allow to easily create uniform small dots - only thing I can think of is using something mechanical to hit the water droplets at tips to effectively launch tiny droplets. (Imagine shuriken (stars or blades) breaking droplet, and water landing) - still we would not have control
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how to control solidification rate in exothermic process - maybe easy, but we would need something like fans or coolant, otherwise we would form big drops at a spot due increased nucleation rate
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how to introduce CO2 fast enough - we would have to have a very strong CO2 environment, somehow not let it solidify at tip. Also this reaction is very slow (maybe that is only the case at bulk solidification). Maybe the whole process would be very slow
Does this process already exist? If it does - any resources related to it would be helpful. If not, Why? Is it because we have not been able to solve the issues I listed, something I did not list? Would this be practical (economically)? I can definitely see both artistic and engineering use cases, and both of those can allow some big budgets.
no, afaik kilning of clay is basically baking clay (I think that is why we have “brick kilns”) that is basically drying of silica (or some secondary or tertiary silicate chains, or aluminate or borate chains) - removal of water, which is techinically a chemical reaction, but the boring kind. What I am thinking of baiscally making the silicate chain
I’m pretty sure it’s more than just drying and more akin to turning sand into glass. The glazing stage certainly is.
yes and no, turning sand to glass requires temperatures in ball park of 1600 C (close to glass transition temperature of Silica), even with mixing of stuff that will go to down to something like 1200, and the ones I found online were not going to that temperature. At lower temperatures, free silicates start to grow the existing silicate chains, knocking water out. Any glazing observed would be because now we are moving towards a more smoother surface (as in, due to solidification). There plenty other side reactions, but basically at low temperatures, we can only have chain growth or initiate (at this low temperature, initiation is also very slow, and growth is the dominiant mode).