9. Additive Technologies

The principles of additive manufacturing are considered as the creation of three-dimensional objects by connecting materials layer by layer without the use of pre-made, as a rule, based on the data of digital computer 3D models. The classification of additive manufacturing technologies according to the methods of forming and fixing the next layer to be attached and according to the type of energy source for fixing the layer to be attached is given. The fundamental differences between additive technologies and surfacing technologies are indicated. The structural scheme of laser additive manufacturing for forming on the bed is described: (Bed Deposition) as layer-by-layer deposition by laser scanning of the plane above the surface of the previously applied layer of powder and turning on the laser over the points falling into the cross-section of the part. The parameters of laser additive manufacturing process are provided and the requirements for powders for additive manufacturing are indicated. The differences between electron beam additive technologies and laser technologies are indicated. The scheme of the industrial system for electric arc additive manufacturing by direct formation (Direct Deposition) of the hemisphere is considered. The key tasks of electric arc additive technologies are explained, namely, ensuring manipulation of the torch along a given trajectory in accordance with the program, which ensures the creation of the product and the minimization of the stress-deformed state of the part. Recommendations for the selection of electrode (filler) materials for electric arc additive manufacturing are provided.