球磨介质对玻璃渗透氧化铝复合材料微观结构的影响

目的：探讨球磨介质对玻璃渗透氧化铝复合材料微观结构的影响．方法：在粉体球磨时选用了两种不同的球磨介质-玛瑙和Al2O3制备玻璃渗透氧化铝复合材料．采用扫描电镜观察微观形貌，采用EDAX进行分析局部成分．结果：在粉体球磨过程中，玛瑙球磨介质会形成碎屑进入到Al2O3粉体中，在后续的烧结过程中，玛瑙碎屑和Al2O3粉体发生低共熔反应形成先驱玻璃相，阻碍了后续玻璃渗透过程的进行，从而在最终的复合材料中保留了玛瑙碎屑所形成的缺陷孔．而使用Al2O3球磨介质的复合材料中无此缺陷．结论：使用Al2O3球磨介质，可以显著减少氧化铝渗透玻璃复合材料中的缺陷气孔．

Effects of milling media on microstructure of glass infiltration alumina composite

AIM: To investigate the effects of milling media on the microstructure of glass infiltration alumina ceramic. METHODS: Different milling medias were employed in powder milling processes. The microstructure of the samples was investigated by scanning electron microscopy (SEM) and the local composition was studied by EDAX. RESULTS: In the powder milling process, agate granules were doped into Al 2O 3 powder. When Al 2O 3 blanks were partially sintered, eutectic reaction between the agate granules and Al 2O 3 particles led to the formation of colorless glass. The colorless glass was infiltrated into the adjacent Al 2O 3 networks and voids formed. During the colorful glass infiltration, the colorless glass kept solid and hampered the infiltration of the colorful glass into the voids. As a result, the voids became some permanent defects in the glass/Al 2O 3 composites. CONCLUSION: With the change of the milling media, this permanent defect decreases dramatically.