Public domaining of ideas

posted May 24, 2019, 7:18 AM by Anthony Douglas
I got a bit worried over the last couple of days that there might be patent encumberances on some of the ideas here, because it has become clear that there are some key ideas that must not be encumbered.

The fundamental idea of rough deposition followed by milling is under control because it is already published as mold sdm.

However there is one other idea, which is the use of ultrasonic consolidation of powders as a deposition method.  This is very important.  Although it is not terribly useful for making objects directly, it has a great deal of promises for making molds.  

So, I am writing this post now expressly for the purpose of getting this idea out in the public domain so that it cannot be patented.  

The idea is to use the application of pressure and ultrasound, with any mode of vibration including transverse or longitudinal, especially relatively low pressures (in order to give a reasonably practical machine), to consolidate powdered materials such as:

Water soluble materials like salt, urea, or other chemicals.

Hexamine, hard waxes and other materials which are only soluble in substances other than water.

-soapstone or other soft materials which are not water soluble.  These may bind even without ultrasound.

-natural graphite, or synthetic graphite with additives such as niobium or manganese or iron, or other transition elements or additives.  These may be added by ball milling the graphite with finely powdered additive material, or the dissolution of some of the metal in a solvent, mixing it with graphite powder and evaporating the solvent, then maybe milling the result.  This can produce a "sticky graphite" which has almost all the same properties as graphite with regard to machineability, softness, and yet being highly temperature resistant (which allows it to be used to cast titanium, steel and other materials.) , but will stick to itsself much better, and can be compacted into a solid mass with significant strength.  Some patents indicate that mixing pure synthetic graphite with 1 percent manganese and compressing under 2000 psi give a solid with compressive strength of 500 psi.

There are documents describing the use of this in pharmaceutical tablet manufacture, and there is a couple documents in which people are describing the consolidation of metal powders, but rarely for additive manufacturing.  There is only one document that I have found that describes investigation of such ultrasonic consolidation of powders for additive manufacturing, and that is by the company that does the Ultrasonic Consolidation 3d printing like system, which uses normally foils or tapes, but they investigated using aluminum powder, too, just with computer simulation, which isn't really that valuable.

We need to do some experimenting with this kind of material deposition approach asap.  That and the process planning are the only key barriers.  Once you have that, you just add an auto change routing machine and aparatus to do the deposition, and basically the gcode can be run to produce a mold immediately.