Insights of Direct Ink Writing parameters towards dense silicon nitride manufacturing

resumo

This study investigates the influence of printing parameters such as infill patterning (0 degrees and 90 degrees), nozzle diameter (0.41, 0.33, 0.25 and 0.15 mm) and printing speed (5-25 mm.s(-1)), on the printability of Si3N4 parts by Direct Ink Writing (DIW). Firstly, a fixed paste composition was used to evaluate the effect of infill direction, nozzle diameter and post processing (cold isostatic pressing) in the final density, flexural strength and hardness of printed samples. Then, a map was constructed by relating printability with the nozzle diameter and the printing speed. Lastly, the paste composition was adjusted, by controlling the concentration of additives and solids, to improve the printability for small tip diameters (<0.41 mm). Average sintered relative densities of approximate to 97 % and approximate to 550 MPa of flexural strength were attained for samples printed with 0.33 mm tip nozzle diameter, using 0 degrees infill direction, reaching approximate to 99 % and approximate to 600 MPa with cold isostatic pressing as post processing. Further decrease in nozzle diameter size to 0.25 mm resulted in high variability for both densification and flexural strength, because of the high quantity of macrodefects arising from the printing process, highlighting the need to adjust the rheological properties of the ink for a proper extrudability. Increasing the amount of carboxymethyl cellulose in the paste with 37 vol% of solids, increases its stiffness and consequently, larger shear forces are required to induce flow, without phase separation.

palavras-chave

MECHANICAL-PROPERTIES; CERAMIC SUSPENSIONS; PARTICLE-SIZE; BEHAVIOR; RHEOLOGY; PERFORMANCE; FLOW

categoria

Engineering

autores

Faria, MS; Pereira, MJ; Alves, MFP; Fernandes, CM; Figueiredo, D; Oliveira, FJ; Olhero, SM

Grupos

G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
G5 - Materiais Biomiméticos, Biológicos e Vivos

Projectos

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

agradecimentos

M.S. Faria acknowledges the FCT for the PhD grant 2023.04490. BDANA. M.F.R.P. Alves acknowledges the FCT for the PhD grant (2021.06615.BD) . This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020) , UIDP/50011/2020 (DOI 10.544 99/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) , financed by national funds through the FCT/MCTES (PIDDAC) . This study was funded by the PRR-Plano de Recuperacao e Resiliencia and by the NextGenerationEU funds at University of Aveiro, through the scope of the Mobilizing Project of the Innovation Green Agendas "Hi-rEV-Recuperacao do Setor de Componentes Automoveis" (Project no 64 with the application) .r (2021.06615.BD) . This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020) , UIDP/50011/2020 (DOI 10.544 99/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) , financed by national funds through the FCT/MCTES (PIDDAC) . This study was funded by the PRR-Plano de Recuperacao e Resiliencia and by the NextGenerationEU funds at University of Aveiro, through the scope of the Mobilizing Project of the Innovation Green Agendas "Hi-rEV-Recuperacao do Setor de Componentes Automoveis" (Project n degrees 64 with the application) .