3D printing by direct deposition of powders and sintering
The invention describes a method to make three-dimensional objects in accordance with data from a 3D or CAD digital model, by controlled powder deposition without the aid of binders or sintering or localized melting systems or moulds of a shape corresponding to the required geometry. Powder sintering is carried out by applying uniaxial pressure and adequate heating by Spark Plasma Sintering (SPS) technology or by conventional sintering techniques.
Several processes are known for the manufacture of solid objects by deposition of successive layers of dust. Some techniques rely on the application of a liquid binder. Selective Laser Sintering (SLS) or Selective Laser Melting (SLM) instead use a laser beam to selectively sinter or melt the powder deposited layer by layer. However, these techniques are only applicable to certain metals and require the use of very expensive dressings. The purpose of this invention is to propose a technique applicable to any material using low-cost equipment. This is achieved by depositing successive layers of two types of powders in a mold without using any binder. In each layer the powders are deposited in order to occupy complementary portions. The two materials have very different mechanical and sintering properties. By applying uniaxial pressure and adequate heating to the mould, one of the two powders can be compacted to produce a solid object, while the second material can be removed at the end of the process. TRL 4.
- Sintered of various metallic materials (copper, steel, aluminium alloys, titanium alloys, refractory alloys);
- Sintered ceramic materials (alumina, zirconia, titania, complex oxides);
- Sintered metal/metal or metal/ceramic composite materials.
- Low investment cost;
- Can be used with any metal or ceramic material available in powder;
- Possibility to make objects of metal/ceramic composite materials;
- Possibility of making multi-material objects.