以碳化硅(SiC)和不同铝源(多孔Al2O3/纳米Al2O3/Al(OH)3)为起始原料,通过原位反应结合工艺制备莫来石结合碳化硅多孔陶瓷。主要研究了不同铝源及温度对多孔陶瓷抗弯强度、气孔率、线性伸缩率等性能的影响,并采用XRD和SEM分析表征了样品的物相组成与断面形貌。结果表明:以多孔Al2O3为铝源,在1450℃下保温3h制备的碳化硅多孔陶瓷的综合性能最优,其强度为58 MPa,气孔率为41.9%;烧结温度对3种铝源所制备的多孔陶瓷具有相同的影响,随着温度的升高,强度逐渐升高,气孔率逐渐降低,线性收缩率逐渐增大。
Mullite-bonded porous silicon carbide ceramics were prepared by an in situ reaction bonding technique and sintered in air with SiC,using various aluminum source(porous Al2O3/nano-Al2O3/Al(OH)3)as starting materials.The effects of aluminum source and sintering temperature on the flexural strength,porosity and linear shrinkage of the porous ceramic were investigated.The phase composition and fracture morphology of the sample were characterized by XRD and SEM.The results show that:SiC porous ceramics prepared with porous Al2O3 exhibited the optimum properties that the flexural strength was 58 MPa and porosity was 41.9% when sintered at 1450 ℃for 3h.The flexural strength increased,porosity decreased and linear shrinkage increased with increase of sintering temperature for all specimens prepared by various aluminum sources.