反应温度对低品位铝矾土和钛铁矿制备β-Sialon/Ti(C,N)复相粉体的影响

Effect of Reaction Temperature on the Synthesis of β-Sialon/Ti(C,N) Composites from Low Grade Bauxite and Ilmenite

以低品位铝矾土和钛铁矿为原料,焦炭为还原剂在不同温度下进行碳热还原氮化反应(CRN),制备β-Sialon/Ti(C,N)复相粉体,其中钛铁矿与铝矾土的质量比为50∶50,同时对反应产物进行XRD物相分析和SEM显微形貌分析。结果显示:原料反应的最佳温度为1250℃,在此温度下产物物相主要为β-Sialon(z=3)、α-Al2O3、Ti(C,N)和单质铁;在低于此温度下产物主要为莫来石,在较高温度下反应产物主要为AlN。反应产物中,β-Sialon微观形貌呈柱状,AlN主要以片状形态存在,单质铁主要以球状形态存在。

β-Sialon/Ti （C, N） composites were prepared by carbothermal reduction-nitridation reaction （CRN） using low grade bauxite and ilmenite as starting materials at different temperatures, the ratio of ilmenite and bauxite was 50： 50, the composition and microstructure of products were studied by X-ray diffraction （XRD） and scanning electron microscope （SEM）. The results showed that the best reaction temperature was 1250℃, because the phases of products mainly were β-Sialon （z = 3 ）, Ti （ C, N） and Al2O3 at that reaction temperature. When the sintering temperature was under that temperature, products still had the phase of mullite, which illustrated the reaction was not complete. When reaction temperature was higher than the best reaction temperature, the main product was AIN. the the The microstructure of β-Sialon was prismatic; the shape of A1N was lamellar and that of iron was globular