At Aerosint we’ve developed the Selective Powder Deposition (SPD), a technology that allows the user to make 2D patterns with multiple powders in any shape or form they desire. Our goal is to empower you with this technology to make materials and parts like none you’ve seen before. One way to achieve this is via direct pressure assisted sintering on multi-material powder constructs.
This approach uses a high temperature resistant die as used in Hot Pressing or Electric current based sintering methods such as SPS, FAST and PECS. Using our technology the powder is deposited directly into the die without the need of an excess material. Using the bottom punch of the die as a building platform a complex 3D powder structure can be constructed using the materials of your choice. Indeed, one of the strengths of SPD technology is the broad range of compatible materials, ranging from most metals in fine powder form as used in additive manufacturing and powder metallurgy, spray dried ceramics, polymers and more.
The process to fill the dies follow 4 simple steps :
- Mounting the die and bottom punch and aligning it with the deposition head
- Sequential deposition of patterned layers
- Inserting the top punch and lowering the deposit
- Pre-compaction in a press to fix the powder in place
After these 4 steps the powder is ready for sintering. Due to the precompaction the powder is firmly fixed in place, facilitating transport. If the punches are secured in place, this even means we can send prefilled dies via courier service to a sintering provider.
The materials that can be combined are subject to compatibility during sintering. This required an overlap in the sintering windows, the pressure and temperature at which the individual materials densify, and a match in thermal expansion properties. While the latter might sound challenging, functional gradients and simulation driven design can be used to compensate for small mismatches, even allowing co-firing of select pairs of metals with insulating oxide ceramics.