Effects of cement content on the microstructural evolution and mechanical properties of cement-bonded corundum castables
| Autor: | Baokuan Li, Tianbin Zhu, Yawei Li, Qinghu Wang, Liping Pan, Zhu He |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Cement Ladle Microstructural evolution Materials science Process Chemistry and Technology Flake Corundum 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Size increase Surfaces Coatings and Films Electronic Optical and Magnetic Materials 0103 physical sciences Materials Chemistry Ceramics and Composites engineering Composite material 0210 nano-technology Porosity |
| Zdroj: | Ceramics International. 46:4634-4642 |
| ISSN: | 0272-8842 |
| Popis: | The cement-bonded corundum castables are often subjected to great temperature gradient in the service process of purging plugs for refining ladle. The mechanical properties of such castables are of particular interest in the serviceability and the safety of purging plug, which are significantly influenced by the microstructures including the amount, size and morphology of materials. The reported cement contents in compounds of purging plugs are generally low or ultralow, which inevitably limits the adjustable range of the mechanical properties enhancement by regulating their microstructures. In the present research, a serial of comprehensive experiments have been carried out, including the high cement contents (10–15 wt%), so as to further understand the role of cement content on the microstructural evolution and mechanical properties of castables. It is found that the phase compositions and microstructure can be optimized through adjusting the cement content in corundum castables. When the cement content is below 10 wt%, the hexagonal flake CA6 grains are platelet-shaped both in the matrix and at the border of the aggregates, their amount and size increase and distributions are more uniformly with cement content. When the cement content is above 10 wt%, small amount of granular crystals CA2 are detected in matrix, and CA6 crystals transform to equiaxial morphologies after cement content of 10 wt%. This research also provides quantitative relationship between the mechanical properties of the castables and the cement content. Castables with cement content of 10 wt% contain most hexagonal flake CA6 crystals, so that they have the highest CMOR and HMOR after heating at 1600 °C. However, CMOR decreases after cement content of 10 wt% due to the porosity and volumetric expansion from the formation of in-situ CA6 and CA2. |
| Databáze: | OpenAIRE |
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