Particle size for filling resin with metal powder


#1

For a school project I am doing research into printing metal with SLA. For this I tried printing with ferrolite which is an Iron filled resin. The laser of the form2 we have is to weak to print this. To further my research, I was advised to look more into what makes the metal filled resin.

For this we will be using different resins and add metal powder to it and we will also try to print with it. The only thing is that I don’t really know what kind of particle size would be fitting for this. Would I be able to use metal powder from a DMLS/SLM printer which has a particle size of around 20-40 micron?

Does anyone here know what kind of particle size I should use for this?


#2

That research paper discusses multiple metal powders. It sounds like to achieve higher metal percentages you have to add a dispersant. I would limit the scope of this project, otherwise it could snowball into a significant undertaking.


#3

The smallest you can find.
The larger the metal grain, the more rapidly it tends to settle- and when the metal settles on the bottom of the tank the laser can’t get to the resin. You might have better results with thinner layers as well because one problem with filled resins is that the filler does not shrink- thicker layers allow for a gradient of metal particle density that makes the upper portion of the resin layer shrink more than the more densely filled lower area and this causes the parts to curl and pull itself away from the build platform.

Also- avoid bronze powders… ideally you want something light and highly reflective like aluminum to both hold the material in suspension better, and to increase the scattering of the laser light into the matrix of metal particles.