超声辐射在湿法制备Al2O3纳米粉中的作用

在超声场中,采用湿化学法制备了碱式碳酸铝铵前驱体,通过改变超声频率、超声功率,在沉淀阶段和陈化阶段同时引入超声辐射的作用的情况下,研究了超声辐射对前驱体向氧化铝转变过程的影响.结果表明:超声频率越高,α-Al2O3的形成温度降低而结晶程度提高.超声功率越大,前驱体一次颗粒粒径越细小,α-Al2O3的形成也越容易,但是由于团聚的存在,过大的超声功率反而增加α-Al2O3形成的难度.在陈化过程中继续施加超声辐射,更易得到细小分散的前驱体,有利于α-Al2O3的形成.

EFFECTS OF ULTRASONIC WAVE RADIATION IN PREPARATION OF NANO-ALUMINA POWDER BY CHEMICAL WETTING PROCESS

Ammonium aluminum carbonate precursor was synthesized by the wetting chemical method in an ultrasonic field. By changing the ultrasonic frequency and supersonic power and including an ultrasonic wave in the precipitation process and the ageing process, the influence of ultrasonic power on a phase alumina formation during the precursor to alumina in calcination was studied. The results reveal that the a phase alumina formation temperature becomes lower with the increase of ultrasonic frequency. With the increase of ultrasonic power, the particle size of the precursor decreases and a phase alumina formation becomes easy. However, owing to the aggregation of precursor particles, if the ultrasonic power is too high, a phase alumina formation will become difficult. When the ultrasonic wave radiation is also used in the aging process, a tiny and dispersive precursor can be obtained, which is beneficial for the formation of a phase alumina.