Sintering mechanism and properties of corundum-mullite duplex ceramic with MnO2 addition

Influence of zirconia on the sintering behaviour and mechanical properties of reaction-sintered mullite-based composite ceramics

“…The maximum bulk density of the AZS6 ceramic was 2.72 g cm –3 , while the flexural strength was only 84.1 MPa. This can be attributed to the introduction of zirconia, which distorted the lattice and increased the mass transfer, promoting the reaction between Al 2 O 3 and SiO 2 (Feng et al , 2022). In addition, rod-shaped mullite crystals were staggered and connected to form a dense network structure (red ellipse in Fig.…”

“…The maximum bulk density of the AZS6 ceramic is 2.72 g/cm 3 , while the flexural strength is only 84.1 MPa (Fig. 4a, 7a) This can be attributed to the introduction of zirconia, which distorted the lattice and enhanced the mass transfer, promoting the reaction between Al2O3 and SiO2 (Feng et al, 2022).…”

Preparation and characterization of high-performance ceramic proppant from recycling utilization of oil-based drilling cuttings pyrolysis residues

“…Figure 9 c showed the bulk density and apparent density of formula B0 with different dosages of MnO 2 . With the increase in the MnO 2 dosage, the sintering temperature and the density showed a descending tendency, indicating that a low-temperature liquid phase was formed during the sintering process, on account of the excellent sintering ability of MnO 2 27 , 41 . Simultaneously, variations of breakage ratio and acid solubility with the sintering temperature of proppants were shown in Fig.…”

“…Metallic oxide sintering additives were used to promote the liquid phase formation and the liquid viscosity alteration of the ceramic system, which can significantly improve the performance of proppants 40 , 41 . In this section, the performances of ODCPRs ceramic proppants with different mass fractions of V 2 O 5 and MnO 2 additives at various sintering temperatures were studied.…”

“…10 b, the peak intensity of corundum and mullite phases of samples containing MnO 2 additives were very similar to formula B0. The reason was Mn 4+ was able to dissolve into the corundum phase and replace Al 3+ to form a finite solid solution during the sintering process, which caused the lattice distortion and promotion of grain growth, reduction of sintering temperature, and the densification of structure 27 , 36 , 41 , 47 . Whereas, the peak intensity of anorthite and celsian was enhanced with the increase of the MnO 2 additive, indicating the addition of MnO 2 could facilitate the generation of the anorthite and celsian.…”