摘要
研究了在β10－Sialon（Si5．23Al0.77O0．77N7，23）中加入7．26Wt％Nd-黄长石固溶体（Nd2Si2AlO4N3）组份的反应过程和致密化行为．烧结过程中，稀土元素先进入α－Sialon；随温度的升高，稀土元素存在于晶界玻璃相中，并在退火过程中以黄长石相析出．对热压及经退火处理的样品，研究了其在1000～1400℃的氧化行为．1000℃氧化时，作为晶界相的黄长石固溶体并不会导致样品开裂．但在更高温度氧化时，氧化后的表面存在择优取向的A－Nd2Si2O7晶粒，且由于Nd离子的表面偏析使表面氧化层软化而形成气泡．
The formation behavior of the composition of β10-Sialon(Si5.23Al0.77O0.77N7.2 3)plus 7.26wt%Nd-meilite sclid solution (Nd2Si2AIO4N,3) prepared by pressureless sintering was studied. Nd ionsin the composition enter α- sialon at low temperature, dissolve in the liquid phase of the materialwith temperature increasing. Melilite solid solution can be formed as a grain boundary phaseof the ceramics by heat-teatment at 1550℃ for 24h. The oxidation behavior of the hot-pressedand post-sintered samples was also investigated in the range of 1000-1400℃. The melilite solidsolution doesn't canes severe cracking of the material in oxidation at 1000℃. At high temperature,the oxidized surface of the sample contains preferentially oriented A--Nd2Si2O7 grains and bubbles,which are formed because of the decrease of the silicate viscosity, incurred by the accumulation ofNd ions to the surface.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
1998年第6期853-858,共6页
Journal of Inorganic Materials
基金
国家自然科学基金!59572009
