Full Record for Micrograph 193
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- Micrograph no
- Brief description
- MgO-C Refractory Brick
- brick , carbon, ceramic , composite material , graphite , magnesia, refractory
- Ceramic, Composite
- MgO 50-90, C 8-37 (wt%), remainder Al, Si metal addition
- Standard codes
- Natural graphite flakes are mixed with MgO aggregate, metal powder and phenolic resin binder. Bricks are pressed and heated to cure and decompose the resin before in situ firing in reducing atmosphere. The metal additions getter oxygen forming ceramic phases at high temperature so protecting the carbon from oxidation and acting as a bond improving hot strength.
- Linings of primary steelmaking furnaces, all areas of basic oxygen furnaces and at the slag line of electric arc furnaces.
- Sample preparation
- Polished and unetched.
- Reflected light microscopy
- Length bar
- 200 μm
- Further information
- This micrograph is of a specimen which has been pressed from either side during fabrication, with the bright graphite flakes appearing edge on. Compare with micrograph 194.
The MgO grain is polycrystalline and porous. The anisometric microstructure means the brick properties are anisotropic and so the bricks orientation must be carefully controlled on installation. These are true composite materials using ceramic (MgO, natural graphite), metal (Si, Al additives), and polymer (phenolic resin) components.
- Prof W E Lee
- Department of Engineering Materials, University of Sheffield
- Licence for re-use
- Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales
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