Preparation of self-bonded products on the base of Fe-Si3N4 at low temperature

The Fe-Si3N4 powder, synthesized by flashing combustion process, is considered as a new-style raw material for the high temperature condition, but its fine performance has not been recognized. The Fe-Si3N4 powder less than 74 μm was made into samples of 50 mm in diameter and 80 mm in height under a molding pressure of 250 kN. The apparent porosity, bulk density and strength resistance of the samples were measured by drilling a cylinder of 36 mm in diameter and 50 mm in height in the samples, which were sintered at 1 500 ℃ for 3 h under the air condition. SEM, EDS and X-ray diffraction were employed to study the sintered samples. All the results showed that with Fe-Si3N4 as the raw material and no subsidiary materials, a refractory on the base of Fe-Si3N4 could be prepared at low temperature under the air condition with the combining action of Fe3Si, which originated from the material and was made by the reaction between Fe and Si3N4.