Additive Manufacturing of Silicon Nitride Ceramic Floatation Spheres with Excellent Mechanical Properties

Abstract

Silicon nitride (Si3N4) ceramic materials are increasingly being used in deep-sea pressure-resistant applications because of their high compressive strength-to-weight ratio. In the present study, Si3N4 ceramic floatation spheres with an outer diameter of approximately 101 mm are successfully batch produced and evaluated. The implementation method was to prepare Si3N4 ceramic hemispherical housings and pair them together. In order to improve the safety of the joint, the hemispherical Si3N4 housings were gradually thickened from 1.80 to 2.50 mm at the equator near the joining surface, based on a 3D model with additive manufacturing technology. The weight-to-displacement ratio of the prepared floatation sphere is approximately 0.34 g/cm3. The flexural strength, compressive strength of the material and the collapse strength of a number of Si3N4 floatation spheres were tested to be 1150, 3847, and 205 MPa, respectively, to confirm the reliability of the process. Additional sustained and cyclic hydrostatic pressure tests simulating the full ocean depth working conditions are carried out on several Si3N4 floatation spheres, which perform very well and do not fail.

High-Performance Nylon-6 Sustainable Filaments for Additive Manufacturing

“…The future direction of the present research may include a comprehensive study of the blending of some of the commonly known reinforcing agents, such as carbon nanotubes and graphene, with Nylon-6, since these substances possess an excellent potential in terms of mechanical resistance, biocompatibility, and various uses in sensors and conductive devices [47,48,49,50,51,52,53]. Blending these substances may lead to the generation of advanced materials to be employed for the additive manufacturing of strong, flexible, and durable structures for a variety of commercial uses [49,54], which need to be investigated via mechanical testing and the microstructure characterization conducted through optical and scanning electron microscope imaging.…”

Additive manufacturing of silicon nitride ceramics: A review of advances and perspectives

“…[47] 2021 Elsevier; (E) reproduced with permission from Ref. [48] 2019 MDPI; and (F) reproduced with permission from Ref. [49] 2020 Elsevier ceramic after sintering at 1750 • C without CIP was only 12 MPa.…”

“…There are also some reports on the functional application of the SLS-3D printed Si 3 N 4 ceramic. Qi et al 48 successfully prepared gradually thickened hemispherical Si 3 N 4 ceramic housings based on SLS. The printed hemispherical green bodies and the sintered Si 3 N 4 ceramic housing are shown in Figure 3E (reproduced with permission from Ref.…”

“…There are also some reports on the functional application of the SLS–3D printed Si 3 N 4 ceramic. Qi et al 48 . successfully prepared gradually thickened hemispherical Si 3 N 4 ceramic housings based on SLS.…”

Colloidal Processing of Complex-Shaped ZrB2-Based Ultra-High-Temperature Ceramics: Progress and Prospects

“…Up to now, complex-shaped oxide ceramics (Al 2 O 3 [97,98], ZrO 2 [99,100], etc. ), typical non-oxide ceramics (SiC [101][102][103], Si 3 N 4 [104,105], etc. ), and precursor-derived ceramics (SiOC [106,107], SiCN [108,109], etc.)…”