Sm_2O_3烧结助剂反应烧结制备β-SiAlON陶瓷

Effects of Bi_2O_3 Doping on the Microstructure and Dielectric Properties of CaCu_3Ti_4O_(12) Ceramics

由于良好的高温强度、抗氧化性、抗腐蚀性能和耐磨性能,β-SiAlOH陶瓷具有高温结构材料的潜在用途,传统的β-SiAlON的制备主要以昂贵的Si3N4为原料,高成本限制了其在工业中的广泛应用。本研究使用廉价的Si粉和Al2O3粉作为原料,通过反应烧结法和后续的高温烧结结合,制备β-SiAlON陶瓷,Sm2O3作为烧结助剂。经过1600℃高温烧结后即可获得了致密的β-SiAlON基体。β-SiAlON的晶粒形貌受烧结剂种类的影响很大,尽管没有添加烧结助剂的试样依然可以获得β-SiAlON相,但是,晶粒形貌为等轴状,且基体多孔。经过Y2O3和Sm2O3分别作为烧结助剂烧结过的β-SiAlON基体致密,晶粒形貌均为高长径比的柱状晶,使用了Sm2O3烧结助剂的β-SiAlON陶瓷,晶粒的长径比高于Y2O3烧结助剂的长径比,这种晶粒形貌有利于陶瓷力学性能的提升。

β-SiAlON ceramics is a potential material that used as structural material in high temperature and corrosion environment due to they possess high high-temperature strength high hardness and good corrosion resistance. The common method for fabricate of β-SiAlON is solid solution using expensive Si3N4 powder as raw material, therefore, the use of β-SiAlON ceramics is limited, to decrease the cost of raw material, β-SiAlON ceramics were synthesized by reaction-bonded associated with post sintering method using cheap Si and Al2O3 as raw material, the Sm2O3 was first used as sintering additive for reaction bonded Si Al ON ceramics. The fully β-SiAlON phase was obtained after poster sintered at 1600 ℃. The morphology of β-SiAlON grains were affected by the type of sintering additive, although the sample without sintering additive shows single β-SiAlON phase, the grains morphology is equiaxed, and the matrix is porous. After sintered with Y2O3 and Sm2O3 addition, the matrix is dense, and the morphology of grains show high aspect ratio, especially for sample with Sm2O3 addition, the grains show higher aspect ratio than that of Y2O3 sintered grains which favor of the mechanical property of β-SiAlON ceramics.