Al2O3-C refractories are widely used as functional elements like nozzles, well blocks, sliding gate plates and stoppers in the continuous casting process of steel production. Application of silicon as a metallic agent...Al2O3-C refractories are widely used as functional elements like nozzles, well blocks, sliding gate plates and stoppers in the continuous casting process of steel production. Application of silicon as a metallic agent in Al2O3-C slide gate plate production is usual. In fact, a non-oxide bond can be generated due to the reaction between silicon and carbon under reducing atmosphere in the plate matrix. This non-oxide bond can enhance the mechanical strength and abrasion resistance. In order to improve the mechanical and thermo-mechanical properties, functional additives can be aimed to lower the sinte- ring temperature and tailor the microstructure. For this reason, the effect of a special solid state sintering aid addition on the microstructure and thermo-mechanical properties of Al2O3-C slide gate plates in the presence of Si as a metallic component has been investigated. Two types of specimens were pressed at 150 MPa, tempered at 200 ℃ and fired in coke bed at 1 400 ℃ , respectively. Physical （ BD and AP ） , mechanical （ CCS and MOR ） and thermo-mechanical （ HMOR ） properties were determined; in addition, phase composition was characterized by X-ray diffraction analysis （ XRD ） and microstructure of specimens was investigated by field emission scanning electron microscopy （FESEM）. Results have shown that the addition of sintering aid increased the generation of cation vacancy in Al2O3 structure which enhanced the cation diffusion and densification process ; consequently, CCS, MOR and HMOR of specimens increased drasticallywhile bulk density and apparent porosity remained un- changed.展开更多
本文采用 X 射线衍射、扫描电镜、分析电子显微镜和高分辩电镜,研究了热压复合SiC-A1_2O_3陶瓷的相组成、晶须、晶须-基体界面间的显微结构。结果表明,复合陶瓷中的晶须为15R 型 SiC,基体为三方晶型的α-Al_2O_3。晶须内有大量的层错和...本文采用 X 射线衍射、扫描电镜、分析电子显微镜和高分辩电镜,研究了热压复合SiC-A1_2O_3陶瓷的相组成、晶须、晶须-基体界面间的显微结构。结果表明,复合陶瓷中的晶须为15R 型 SiC,基体为三方晶型的α-Al_2O_3。晶须内有大量的层错和孪晶;晶须-基体界面间存在一个过渡层,并有一定的取向关系。扫描电镜对样品断口的研究表明,存在晶须拔出和裂纹偏转两种增韧机制。展开更多
文摘Al2O3-C refractories are widely used as functional elements like nozzles, well blocks, sliding gate plates and stoppers in the continuous casting process of steel production. Application of silicon as a metallic agent in Al2O3-C slide gate plate production is usual. In fact, a non-oxide bond can be generated due to the reaction between silicon and carbon under reducing atmosphere in the plate matrix. This non-oxide bond can enhance the mechanical strength and abrasion resistance. In order to improve the mechanical and thermo-mechanical properties, functional additives can be aimed to lower the sinte- ring temperature and tailor the microstructure. For this reason, the effect of a special solid state sintering aid addition on the microstructure and thermo-mechanical properties of Al2O3-C slide gate plates in the presence of Si as a metallic component has been investigated. Two types of specimens were pressed at 150 MPa, tempered at 200 ℃ and fired in coke bed at 1 400 ℃ , respectively. Physical （ BD and AP ） , mechanical （ CCS and MOR ） and thermo-mechanical （ HMOR ） properties were determined; in addition, phase composition was characterized by X-ray diffraction analysis （ XRD ） and microstructure of specimens was investigated by field emission scanning electron microscopy （FESEM）. Results have shown that the addition of sintering aid increased the generation of cation vacancy in Al2O3 structure which enhanced the cation diffusion and densification process ; consequently, CCS, MOR and HMOR of specimens increased drasticallywhile bulk density and apparent porosity remained un- changed.
文摘本文采用 X 射线衍射、扫描电镜、分析电子显微镜和高分辩电镜,研究了热压复合SiC-A1_2O_3陶瓷的相组成、晶须、晶须-基体界面间的显微结构。结果表明,复合陶瓷中的晶须为15R 型 SiC,基体为三方晶型的α-Al_2O_3。晶须内有大量的层错和孪晶;晶须-基体界面间存在一个过渡层,并有一定的取向关系。扫描电镜对样品断口的研究表明,存在晶须拔出和裂纹偏转两种增韧机制。
