喷雾共沉积SiCP/Al复合材料颗粒进入基体机制的研究

本文分析了喷雾共沉积颗粒增强金属基复合材料工艺中颗粒进入金属基体的动力学过程和可能机制,首次提出对于陶瓷颗粒/铝等非润湿系,颗粒将按射入机制进入基体;并由颗粒进入沉积层液膜的力学平衡关系,推导出颗粒按射入机制进入基体时,沉积前所需达到的临界速度表达式。在射入机制和大量实验的基础上,提出了一种新的颗粒加入方法即外部环孔式喷嘴注入法,解决了微细SiC颗粒在基体中分布不均匀、体积分数难以控制和提高等工艺难点,制出了W10 SiC颗粒在基体中分布均匀、体积分数达14.7vol%的SiC_P/Al复合材料。

STUDY OF THE INCORPORATION MECHANISM BETWEEN PARTICULATES AND MATRIX OF SiC_P/Al COMPOSITES BY SPRAY CO-DEPOSITION

In this paper,the kinetic process and the possible incorporation mechanisms areanalvsed between particulates and matrix of particulate-reinforced metal matrix compositesby spray co-deposition,For the first time it is presented that the injection mechanism is theunique incorporation mechanism between ceramic particulates and aluminum matrix,whereceramic particulates are poorly wetted by aluminum melt.Furthermore,the expression ofthe critical deposition velocity of a particulate,above which the particulate could beincorporated into matrix by the injection mechanism,is deduced from the balance of forcesacting on the particulate by the liquid layer of the composite ingot.On the basis of theinjection mechanism and a large number of experiments,a new method is developed to injectSiC particulates into the atomized spray,and W10 SiC_P/Al compsites with low segregation ofSiC particulates and volume fraction of SiC particulates up to 14.7%were obtained.It isseen that the injection mechanism could predict the experimental results effectively.