METHOD FOR PRODUCING A THREE-DIMENSIONAL AUXETIC WITH A CELLULAR STRUCTURE (VARIANTS) Russian patent published in 2022 - IPC B29C64/118 B29C64/153 B22F3/105 B33Y10/00 B33Y80/00 

FIELD: additive technology.

SUBSTANCE: group of inventions relates to the field of formation by methods of 3D printing in the form of a three-dimensional (3D) cellular structure of complex geometry with a negative Poisson's ratio, to be used in various applications, including sports and medicine, as elements of personal protective equipment, as well as in implantology and orthopedics. Described are methods for producing a three-dimensional auxetic with a cellular structure (variants), including building a 20×20×10 mm unit cell, with the lateral edge inclined at an angle of 60 degrees to the horizontal edge, based on various materials: thermoplastic polyurethane (TPU) elastomer, or based on AlSi₁₁Cu. The unit cell is created using solid-state modelling in computer-aided design systems. A three-dimensional auxetic based on a thermoplastic polyurethane elastomer is formed by 3D printing by the fused deposition modelling method with a layer of 300 mcm in thickness at a printing speed of 15 mm/s, at an extrusion temperature of 225°C. A three-dimensional auxetic based on AlSi₁₁Cu is formed by 3D printing by the selective laser melting method with a layer of 30 mcm in thickness, with a scanning speed of 1,650 mm/s, with a power of the laser of 370 W.

EFFECT: creation of a cellular structure with a negative Poisson's ratio, characterised by a complex three-dimensional geometry, with a periodic structure, the possibility of manufacturing by methods of 3D printing from various materials, including polymers and metal alloys, as well as the capacity for absorbing (dampening) and evenly distributing mechanical energy throughout the entire volume of the structure due to the auxetic effect (uniform compression); the value of location of the lateral edge to the horizontal edge used herein creates an optimal Poisson's ratio/mechanical properties ratio.

2 cl, 11 dwg, 2 ex