چكيده به لاتين
Silicon Carbide (SiC) is an advanced ceramic that has been studied over the past 30 years. Aluminum borate is a significant ceramic material due to its excellent mechanical properties, high elastic modulus, high tensile strength, excellent corrosion resistance, good chemical neutrality, high temperature stability, high melting point, light weight, low cost of production and low thermal expansion coefficient that is used as a reinforcement in composites. The purpose of this study is to investigate the methods of aluminum borate synthesis and its effect as an additive on SPS silicon carbide bodies. At first, Al18B4O33 aluminum borate was synthesized in three methods: sol-gel, precipitation and combustion. Then TG / DTA, FTIR, XRD and SEM analysis were performed. The results showed that Al18B4O33 was synthesized in all three methods at 1000 °C. The citric acid plays an important role in controlling the morphology. A self-catalytic mechanism for sol-gel method and a melt salt flux mechanism for both precipitation and combustion methods were proposed. In the next step, silicon carbide was synthesized by SPS using aluminum borate, and performed strength, density, XRD and SEM analysis. The results showed that by adding 5% aluminum borate to silicon carbide and SPS of the samples with 47 MPa at 1650 ° C temperatures can be compared to a relative density of 58.72% and flexural strength of 99.08 MPa. The flexural strength of the sample containing 5% aluminum borate additive has grown by about 100% relative than the non-additive sample. By increasing the percentage of aluminum borate from 5% to 8% weight and SPS of the samples under pressure of 47 MPa at 1650 ° C reduced the strength by 49% and the flexural strength increased to 53.50 MPa.
