无压浸渗制备Si_3N_4/Al复合材料的反应浸渗机理  

Mechanism of Reaction Infiltration of Pressureless Infiltrated Si_3N_4/Al Composite

作　　者：王扬卫[1] 于晓东[1] 王富耻[1] 马壮[1] 康晓鹏[1] 

机构地区：[1]北京理工大学材料科学与工程学院,北京100081

出　　处：《稀有金属材料与工程》2007年第A01期777-780,共4页Rare Metal Materials and Engineering

摘　　要：采用"中断浸渗"方法获得保留了"浸渗前沿"的样品,应用扫描电子显微镜和X射线能谱分析了浸渗界面上的形貌和成分变化,深入讨论了浸渗界面推进过程中的物理、化学反应过程。采用扫描电镜等微观分析手段观察了复合材料显微形貌,探讨了界面反应机理。研究结果表明:浸渗界面推进过程中熔体中的Mg富集在浸渗前沿的预制体上,并与预制体发生反应;Al/Si3N4界面反应产物AlN相形成"楔形"向Si3N4单元心部推进,细观上呈现含毛细通道的胞状辐射形貌,大量毛细通道确保了Al和Si3N4之间的置换反应持续进行;Al与Si3N4的置换反应产物Si绝大部分溶解在铝镁合金熔体中。A special specimen with ＂infiltration front＂ was obtained by ＂infiltration interrupting＂ method, and the morphology and the component change along the infiltration interface were analyzed by SEM and EDS. In addition the physical and chemical reactions during infiltration front advancing process were discussed. The microstructure of Si3N4/Al composites was also investigated by SEM and EDS, and the mechanism of Si3N4/Al interface reaction was studied. It is shown that Mg element in Al-Mg alloy becomes enriched along the infiltration front and on the Si3N4 preform and reacts with the perform. AlN, displacement reaction product between Al melt and Si3N4, extends into the center of the Si3N4 unit in the shape of ＂cuneiforms＂, and it is found that the generated AlN products layer is in radiate celluliform shape with many capillaries. It is these capillaries that keep the reaction between Al and Si3N4 going on and most of the displacement product Si is dissolved in Al-Mg melt.

关 键 词：无压浸渗 复合材料 SI3N4 界面反应 浸渗机理 

分 类 号：TB333[一般工业技术—材料科学与工程]