用高能超声法制备微细颗粒增强金属基复合材料

PREPARATION OF FINE PARTICULATE METAL-MATRIX COMPOSITES BY HIGHINTENSITY ULTRASOUND

用高能超声法将微米级陶瓷颗粒均匀分散于Ａｌ液中，获得了微细颗粒增强Ａｌ基复合材料．

High-intensity ultrasound have ben introduced into liquid aluminium to disperse ceramic particles which are finer than 10μm in the melt homogeneously so as to prepare fine particulate MMCp with perfect microstructure. SiC and Si3N4 particles of average size of 3.5 and 1.0μm respectively were mixed with acetone and ultrasonically agitated for several minutes. The particles were allowed to settle and the excess actone was decanted. Then the particles are incorporated with Al-Mg melt. The melt was irradiated with 20kHz and 15μm amplitude. Finally, the melt with the dispersed particles was solidified in metal mould. The metallographic examination of the fine particulate MMCp made by high-intensity ultrasound shows that the pretreated particles are easy to be added into liquid aluminium. All the particles are well wetted by the Al-Mg matrix. The fine SiC and Si3N4 particles are homogeneously dispersed in matrix without any cluster or segregation, which indicates that high-intensity ultrasound also has the ability to stir the melt.