不同元素改性氧化铝的耐磨性能

WEAR RESISTANCE OF ALUMINA MICROSPHERES MODIFIED BY DIFFERENT ELEMENT

采用饱和浸渍法制备了由锌、镁、磷、硅等不同元素改性的氧化铝,并模拟浆态床反应过程,利用浊度分析方法测定了不同元素改性氧化铝微球的耐磨性能。结果表明:上述改性处理并不能改变氧化铝微球的物理磨损性能,但相对于未改性的氧化铝,经不同元素改性的氧化铝微球在水热条件下的耐磨性能均得到提升,其中以正硅酸四乙酯为原料的硅改性氧化铝耐磨性能最佳。采用X射线衍射、扫描电镜、傅里叶变换红外光谱对产生这种差异的原因进行分析,发现硅改性形成的硅羟基会取代氧化铝表面的铝羟基形成Al—O—Si键,减弱了氧化铝对水的吸附,提高了氧化铝抗水合能力,进而提高了硅改性氧化铝微球水热条件下的耐磨性能。

The modified aluminas with different elements,such as zinc,magnesium,phosphorus and silicon,respectively,were prepared by saturation impregnation method,and the wear resistance of the modified alumina microspheres was determined by turbidity analysis.The results showed that the physical wear resistance of modified alumina microspheres was not changed,but the wear resistance of the modified alumina microsphere was improved under hydrothermal condition,among them,the wear resistance of silicon-modified alumina with tetraethyl orthosilicate as raw material was the best.X-ray diffraction,scanning electron microscopy and Fourier transform infrared spectroscopy were used to analyze the cause of the difference,it was found that the silicon hydroxyl group formed by silicon modification could replace the aluminum hydroxyl group on the surface of alumina to form Al—O—Si bond,which weakened the adsorption of water and improved the hydration resistance of alumina,furthermore,the wear resistance of silicon-modified alumina microspheres was improved under hydrothermal condition.