High‐temperature flexural strength of SiC ceramics prepared by additive manufacturing

Abstract

Silicon carbide (SiC) ceramics, as a kind of candidate material for aero-engine, its high-temperature performance is a critical factor to determine its applicability.This investigation focuses on studying the high-temperature properties of SiC ceramics fabricated by using additive manufacturing technology. In this paper, SiC ceramics were prepared by combining selective laser sintering (SLS) with precursor infiltration and pyrolysis (PIP) technique. The microstructure, phase evolution, and failure mechanism after high-temperature tests were explored. SiC ceramic samples tested at room temperature (RT), 800°C, 1200°C, 1400°C, and 1600°C demonstrated bending strengths of 220.0, 226.1, 234.9, 215.5, and 203.7 MPa, respectively. The RT strength of this material can be maintained at 1400°C, but it decreased at 1600°C.The strength retention at 1400°C and 1600°C were 98% and 92%, respectively. The results indicate that the mechanical properties of SiC ceramics prepared using this method have excellent stability. As the temperature increases, the bending strength of the specimens increased slightly and reached the peak value at 1200°C, and dropped to 203.7 MPa at 1600°C. Such an evolution could be mainly due to the crack healing, and the softening of the glassy phase. K E Y W O R D Shigh-temperature flexural strength, polymer impregnation process, selective laser sintering, silicon carbide

Properties of SiC‐Si made via binder jet 3D printing of SiC powder, carbon addition, and silicon melt infiltration

“…34 Among the limited mechanical property data reported for SiC processed by AM techniques, Xu et al reported flexural strength data between 203.7 and 234.9 MPa from tests performed between 800 and 1000℃ for materials processed by selective laser sintering and preceramic polymer IP. 35 The lower values obtained in that study, compared to the results reported here, could be explained by the relatively low densities obtained by the IP of polymeric precursors for silicon carbide. 35 Figure 8 shows values of Young's modulus as a function of temperature for the different processing conditions.…”

“…35 The lower values obtained in that study, compared to the results reported here, could be explained by the relatively low densities obtained by the IP of polymeric precursors for silicon carbide. 35 Figure 8 shows values of Young's modulus as a function of temperature for the different processing conditions. The sample processed with 0 IP cycles had the lowest stiffness, consistent with the high level of porosity.…”

Dynamic Nuclear Polarization of Silicon Carbide Micro- and Nanoparticles

“… 38 The remaining samples ( Figure 1 a, green, orange, and red curve) feature diffraction peaks at 34.1, 41.5, and 65.5° that are in agreement with an α-SiC phase. 39 XRD results of the α-SiC samples are consistent with the 6H-SiC polytype; however, other possible polytypes such as 4H-SiC may also exist. 40 Notably, α-SiC can consist of many different polytypes due to the different stacking sequences of carbon and silicon atoms in its crystal structure.…”

High‐temperature strength of liquid‐phase‐sintered silicon carbide ceramics: A review

“…83,84 These results suggest that the structure of the grain boundaries is also strongly dependent on the additive composition and heat treatment conditions. 56,57 SSiC ceramics exhibit flexural strengths of <600 MPa 6,[70][71][72][73] ; however, some LPS-SiC ceramics reveal behavior and the ceramic propert larly in the Sejnène region, northw the chemical composition, these c terized by high iron contents who of the ceramic materials is well k of fluxing agents as alkali and alk are necessary for low temperatur considered materials consist entir containing impurities, mostly ill iron, which serve as fluxing agen at low temperature [3][4][5][6] and appeare physical and mechanical propertie ramic materials.…”