Papers by Author: Xin Lu

Abstract: The utilization of steel slag as resource is very important in the circle economy of metallurgy industry. Because the composition of steel slag is similar to that of the raw materials of ceramic industry, the sintering process of ceramics with steel slag as one of the raw materials was studied, and the ceramic products of high performance were abstained. Based on the study above, the microstructure of slag ceramic and its effect on the performance of ceramic were studied combining the analysis methods of SEM, DTA and XRD and the software FactSage. It’s found that the diopside phase was formed in the sintering process, which has significant effects on low temperature sintering and ceramic strength improving. Simulation by software FactSage showed that the diopside phase appears when the content of the steel-slag reaches 25%, while the content of slag is higher there are more diopside phase generation.

Abstract: In the study, the spark plasma sintering (SPS) method was adopted to fabricate Si3N4 ceramics with Y2O3-MgO additives. Specimens with different grain dimensions, grain shapes, α/β phase ratios, densities were obtained by changing the heating rate and dwell time of SPS. The relationship between the microstructure and the thermal conductivity was studied. Results show that the heating rate and the dwell time have great influence on the microstructure and properties of Si3N4 ceramics. Both equiaxed and columnar β- Si3N4 grains are formed during sintering, but the thermal conductivity of Si3N4 ceramics is affected only by columnar grains. The thermal conductivity of the ceramics increases together with the formation and the growth of the β- Si3N4 columnar grains.