碳化硅颗粒增强铝基复合材料的无压浸渗反应机理探讨

为探讨SiCp/Al复合材料无压浸渗反应机理，利用XPS鉴定了SiC预制体浸渗前沿界面上的反应产物结构，采用HRTEM研究了SiCp/Al基复合材料的界面结构。结果表明，浸渗与未浸渗部分之间的界面上存在MgO,Al2O3和ZnO诸化合物，没有发现氮的化合物，在SiC相与铝相的界面上仅存在MgAl2O4相，MgAl2O4相几乎连续地包敷在SiC颗粒上，这表明，高温下SiC与熔Al合金接触后，SiC颗粒表面上的SiO2与Al，Mg,Zn诸元素发生了放热反应，从而降低了表面张力，提高了湿润性，促进了自发浸渗。

Investigation on Reaction Mechanism of SiC Particulate Reinforced Aluminum Matrix Composite Prepared by Pressureless Infiltration

In order to investigate the pressureless infiltration reaction mechanism for a SiC/Al composite , the reaction products structures at the front interface of the SiC preform were identified by means of XPS and TEM The results of the XPS analysis show that the compounds such as MgO, Al 2O 3 and ZnO are present at the interfacial region between the infiltrated and uninfiltrated parts of the SiC preform and no nitrogen compound is found The HRTEM shows that there is only a MgAl 2O 4 phase existing at the interface between SiC phase and aluminum alloy matrix phase and the MgAl 2O 4 phase covers almost the whole SiC particulate surface It is suggested that the exothermic reactions take place between the SiO 2 on the surface of SiC particulate and the Al, Mg and Zn elements after the contact of the molten Al with the SiC particulate Hence the surface tension is decreased, the wettability is increased and the spontaneous infiltration is promoted