Effects of Temperature on the Synthesis of SiAlON and SiAlON Composite Material from Aluminium Dross
Volume 2, Issue 3, Pages 76 - 80
SiAlON and a SiAlON composite material were synthesized from aluminium dross by adding a certain amount of silicon, SiO2 and Al using aluminothermic (silicothermic) reduction and nitridation. The effects of temperature on the synthesis were investigated. For this purpose, the apparent porosity (AP), bulk density (BD), phase composition and microstructure of specimens fired at 1000 ºC for 1 h, and then heated to 1300 ºC, 1350 ºC, 1400 ºC, 1450 ºC and 1500 ºC for 4 h, respectively, were etermined. The results showed that singlephase β-SiAlON can be synthesized at 1000 ºC / 1 h and then at 1450 ºC / 4 h with an N2 flow of 0,5 l/min. The apparent porosity of the specimens was highest at the latter temperature. In the experiments for synthesizing SiAlON composite material, SiAlONs occurred in hexagonal prisms, growing among corundum crystals or on the surface of it. The optimum temperature was between 1400 ºC and 1450 ºC.
SiAlON synthesis, aluminium dross, secundary raw materials
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