无压浸渗法制备B_4C/Al复合材料研究

Fabricating Aluminum Toughed Boron Carbide Composites by Pressureless Infiltration Technology

采用无压浸渗法,分别以纯铝、超硬铝LC4和铸造铝合金9Si-3Mg-1Zn为渗体和碳化硼陶瓷预制体进行复合,制备出有高陶瓷体分比的B-Al-C陶瓷-金属复合材料,弯曲强度350～600MPa,韧性5～9MPa·m-1/2,采用扫描电镜,X射线衍射仪和金相显微镜和透射电镜对材料的微观结构进行分析,分析结果表明材料界面复合良好,在碳化硼和铝的界面有薄的Al3BC反应层生成使碳化硼与铝紧密结合,在复合材料中碳化硼形成连续的骨架结构,金属相起到增韧、增强的作用。

Cermet composites of high ceramic fraction are made by infiltrating the aluminum(L4) or aluminum alloys(LC4 )and casting aluminum alloy into boron carbide ceramic preforms during a pressureless infiltration process The flexure strength are from 350 to 600 MPa, and the fracture toughness are from 5 to 9 MPa·m-1/2The microstructures of the composites are observed by an optical microscope,the transmission electronic microscope and the scanning electron microscope and the phases are analyzed by X ray diffractometer The results indicate that a well interface connect can be achieved An reaction zone of Al3BC connect both the aluminum and the ceramic toughly An connected ceramic frame are formed in the composites and the composites are toughed by the metal