Search academic texts

Information × Registration Number 0223U004055, 0123U100014 , R & D reports Title Novel technologies of products formation using 3D printing and welding popup.stage_title Head Yurzhenko Maksym V., Доктор технічних наук Registration Date 22-08-2023 Organization Yurzhenko Maksym V. popup.description2 In the work, polylactide (PLA) filled with a carbon filler - carbon black (CB) with a segregated (ordered) structure was used to manufacture composite materials, filaments based on them, and 3D products from them. It was found that the content of CB in the range of φ = 2.5–5 vol.% in the PLA matrix leads to the formation of a continuous electrically conductive phase with an increase in the electrical conductivity σdc above the percolation threshold. It was found that increasing the content of CB from φ = 1 vol.% to φ = 7 vol.% in the composites causes minor (due to the segregated structure) phase changes in the polylactide matrix and improves the thermal properties of the composites. Conductive filaments for 3D printing by deposition method (FDM) were produced and 3D printed with them. Electrical conductivity varies within σdc = 3.1•10−11 − 10•10−3 S/cm for filaments and σdc = 3.6•10−11 − 8.1•10−4 S/cm for final 3D products . For the manufacture of embedded heating elements for welding parts from polymer materials, including those formed by 3D printing, electrothermal processes in pyroresistive composites based on high-density polyethylene (HDPE) containing 8 vol.% carbon black (CВ), 8 vol. .% carbon fibers (CF) and their mixtures 4 vol.% CB + 4 vol.% CF. It is shown that after a short heating time the equilibrium temperature Te is reached in the sample. Due to the PTC effect, the composites exhibit a self-regulating effect relative to Te. The possibility of using such pyroresistive composites for welding of polymer materials with the use of an embedded heating element (EHE) made of pyroresistive material has been proven. Studies of the sensor properties of the created EHE also showed the possibility of their application and the high rate of change of their electrical parameters during deformation both before and after welding, and therefore such EHE can be sensors for monitoring the quality and performance of welded joints. Product Description popup.authors Yurzhenko Maksym Volodymyrovych popup.nrat_date 2023-08-22 Close