Study On Sintering And Performance Of Al₂O₃-Al-Si Materials

This paper used aluminum metal powder, metal powder and alumina powder as the main raw materials sintered by nitriding reaction, mainly researched the sintering aid, sintering additives, sintering temperature and time to the effects of the sample volume density, compression strength, physical phase composition and micro-structure, in order to determine the optimum sintering process; the raw materials were sintered by discharge plasma sintering (SPS).The sintering temperature, sintering time and sintering pressure on the effects of sample volume density, compressive strength, phase composition and microstructure were mainly discussed to analysis the sintering process; the research methods such as XRD, SEM and EDS were used for testing. The main results were as follows:The Al2O3-Al-Si materials adding TiO2sintering additives were sintered by nitriding sintering. The results showed that:the material’s volume density and the compression strength was2.86g·cm-3and76.94MPa respectively, sintered at1500℃for5h. The main crystal phase was β-Sialon phase, meanwhile contained a small amount of corundum phase. The microstructure analysis showed that the structure of sample was more densification, and P-Sialon grain was about1μm in diameter and1-2μm in length.The materials adding Fe2O3sintering additives were sintered though nitriding sintering. The results showed that sintered at1500℃for5h, the material’s volume density was2.92g·cm-3and the ompression strength was85.44MPa. The sample only existed P-Sialon phase, with about1μm in diameter and1-2μm in length.Compared with two kinds of sintering additives, the sample volume density and compression strength adding Fe2O3was higher. The synthesis quantity of P-Sialon phase was more, and the material’s microstructure was dense.The Al2O3-Al-Si material was sintered by SPS at1000℃for6min and sintering pressure of40MPa. The sample volume density was2.27g·cm-3, and the compressive strength was225.3MPa. The main crystal phase was Si, meanwhile contained a small amount of corundum phase. The microstructure showed that the sample contained a lot of flocculent fibers and its chemical composition was9.29%,18.67%,29.32%,32.56%of Si, Al, O and N. It proved that having nitrides generated in sample.