Synergistic influence of SiC and C₃N₄ reinforcements on the characteristics of ZrB₂-based composites

Abstract

In this work, ZrB 2-SiC and novel C 3 N 4-doped ZrB 2-SiC composites were manufactured at 1850° C under an external load of 40 MPa for 6 min via spark plasma sintering. The effects of C 3 N 4 on the mechanical characteristics (flexural strength, Vickers hardness, and fracture toughness) and microstructure of the ZrB 2-SiC-based composites were investigated. By adding 5 wt% g-C 3 N 4 , a fully dense ceramic composite was fabricated, compared to the C 3 N 4-free ZrB 2-SiC composite with a relative density of 95%. Removal of ZrO 2 and B 2 O 3 from the surface of ZrB 2 particles via chemical reactions with C 3 N 4 , and the in-situ synthesis of ZrC and BN as new phases were studied by XRD and SEM analyses. Indentation fracture toughness, flexural strength, and Vickers hardness improved from 4.5 MPa.m 1/2 , 460.2 MPa and 17.4 GPa to 6.1 MPa.m 1/2 , 580.2 MPa and 21.2 GPa, respectively, by adding g-C 3 N 4 to the ZrB 2-SiC ceramic.

Non-catalytic applications of g-C3N4: A brief review

“…The mechanical properties also have been improved by adding 5 wt% C 3 N 4 to the ZrB 2 matrix, due to densification enhancement and grain growth reduction. The Vickers hardness, fracture toughness, and flexural strength have been increased from 10.1 GPa, 1.9 MPam ½ , and 187.6 MPa to 16.2 GPa, 5.4 MPam ½ , and 516.4 MPa, respectively [33].…”

Acid protonation promoted different crystal phase structure silicon carbide-based carbon nitride composites to enhance the photocatalytic degradation of dye wastewater

“…36 Similarly, studies on silicon carbide and carbon nitride composite catalysts have been reported, mainly including g-C 3 N 4 -SiC-Pt, 37 ZrB 2 -SiC/C 3 N 4 . 38 Its applications mainly include the degradation of wastewater such as rhodamine B, alizarin red, and tetracycline, photocatalytic hydrogen production, and the construction of pressure-resistant materials. However, the SiC used in previous research reports are all commercial micro- or nano-powders, and its crystal form is a mixed crystal phase of α-SiC and β-SiC.…”

Influence of TiN addition on densification behavior and mechanical properties of ZrB2 ceramics

“…(Zr,Ti)B 2 -(Zr,Ti)N ceramic composite is fabricated due to the in-situ synthesis and penetration of ZrN and TiB 2 as the result of TiN addition to the ZrB 2 ceramic and their chemical reactions during the spark plasma sintering [40]. The Appearance of insitu synthesized h-BN, the solid solution of (Zr,Ti)B 2 , and ZrN as well as ZrO 2 was proved in TiN-doped ZrB 2 -SiC leading to mechanical properties improvement [41].…”