The principle of shell objects creation Method of controlled
sintering in the volume of powdered technical materials - especially polymers,
metal materials, glasses and ceramics - to achieve the desired volume structure. Preferably, this technical solution is intended to produce objects with the occurrence of thin walls (shells), the construction of which is significantly easier on the basis of this invention than with the existing methods of additive technologies building volume by
layers - e.g. no support structures are required. This physical principle enables the creation of a primary temperature field through several mutually intersecting beams of penetrating coherent
radiation (1), through which cohesion is created between the particles of the
powder material. The primary temperature field (3) is moved in a determined manner in the
working space to achieve the construction of the desired object (4) by transformation from the
powder material. The
powder material is used for processes in two forms: (i) loose powder, in which the
volume loss of the transformation from the powder state to liquid and
solid is supplemented by gravitational forces from the stock located above the place of the process; (ii) powder compacted by pressing, in which the purposeful production of an object with the required
porosity is assumed. The transformation from the powder material to the desired object is, in principle, carried out by the action of the primary temperature field (3) in two ways: (i) Melting, during which the particles of the powder material intended for fusion
metallurgy processes are melted, mixed in a
liquid state and subsequent cooling to create a compact volume of the
manufactured object; (ii) By
sintering the powder in a
solid state, in which the particles of the powder material intended for the
powder metallurgy processes are interconnected by the processes of
atomic diffusion leading to the joining of the powder particles, increasing the density, recrystallization and
grain growth. The resulting product in this case is a powder compact After creating the compact and its separation from the powder material, usually takes place further
processing with a primary temperature field - final
sintering - in order to significantly reduce the
porosity and increase the mechanical properties. In all phases of the described processes, it is advantageous to use a secondary temperature field formed by several mutually intersecting beams of penetrating coherent
radiation, through which the
temperature gradient between the created and created volumes is reduced and the
material structure of the created objects is homogenized.