Wettability-Enhanced SiC-Graphite Synergy in Al₂O₃-SiC-C Castables: Carbon Resource Comparation, Sintering Response,...

Area of Science:

• Materials Science
• Ceramic Engineering
• Refractory Technology

Background:

• Established research exists for Al2O3-SiC-C refractories in blast furnaces.
• Gaps identified in understanding SiC-modified graphite and alternative carbon sources' performance.
• Need for laboratory and industrial trials on advanced refractory castables.

Purpose of the Study:

• Investigate sintering, mechanical properties, and service performance of Al2O3-SiC-C castables.
• Evaluate varying contents of modified flake graphite, pitch, and carbon black.
• Analyze the role of SiC modification on graphite and its impact on refractory behavior.

Main Methods:

• Synthesized Al2O3-SiC-C castables with different carbon sources.
• Characterized samples using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Energy Dispersive Spectroscopy (EDS).
• Conducted laboratory and industrial trials to assess performance.

Main Results:

• SiC-modified graphite induced microcrack-toughening via thermal expansion mismatch, enhancing mechanical properties.
• SiC layer improved graphite wettability and oxidation resistance, contributing to erosion resistance via matrix pinning and crack deflection.
• Optimal performance observed with 1 wt.% modified flake graphite; however, microcracks limited net erosion resistance improvement.
• Industrial trials revealed an unexpected water reduction mechanism with the optimal formulation.

Conclusions:

• SiC modification of flake graphite offers synergistic benefits for Al2O3-SiC-C refractories, enhancing mechanical properties.
• Modified graphite contributes to improved erosion resistance, though microcracking presents a counteracting effect.
• 1 wt.% modified flake graphite represents an optimal composition, but requires further investigation into its water reduction phenomenon.