【摘要】 将 Si₃N₄原料预热处理以及预合成 Si₃N₄-Al₂O₃-Y₂O₃系的晶界相,两者按适当比例制得的坯体,经无压烧结得到相对密度>97%的 Si₃N₄烧结体。其高温抗弯强度达400MPa（1300℃下）,比通常工艺（未经处理的）制得的强度相应提高约25%。用 SEM、TEM 对这种 Si₃N₄试样的显微结构进行了研究分析,解释了强度提高的原因。更多还原

【Abstract】 The bending strength of Si₃N₄ compacts prepared by pre-heating Si₃N₄ powdersand pre-synthetic grain-boundary phase of Si₃N₄-Al₂O₃-Y₂O₃ system and then sin-tered to a relative density>97% is 400 MPa（at 1300℃）,which is 25% increasedas compared with,that obtained by usual technique（no heat treatment）.The microstructures of the specimens were studied by SEM and TEM.Thereason of improving the mechanical properties was discussed in this paper.更多还原