采用无压浸渗法制备了B4C-CeB6/Al复合材料,并对其进行了力学性能测试。B4C-CeB6/Al复合材料的密度、抗弯强度、断裂韧性相比单一B4C材料都有很大的提高,而硬度有所降低。其抗弯强度值为409.47MPa,比单一碳化硼提高了39.32%;断裂韧性值6.58MPa·m^1/2,比单一碳化硼提高了78.80%。B4C-CeB6/Al复合材料的抗弯强度和断裂韧性的提高主要有两方面的作用:一是由于原位生成的CeB6和B4C颗粒之间热膨胀系数的不匹配产生残余应力,从而引起裂纹偏转起到增韧的效果;二是渗入金属铝的延展性在复合材料中得以体现,使复合材料韧性增加。
B4C-CeB6/Al composites were fabricated by pressureless infiltration technology. The mechanical properties of B4C-CeB6/Al composites were tested. The density, the flexibility strength and the fracture toughness of B4 C-CeB6/Al composites were greatly improved compared with those of monolithic boron carbide, but the hardness decreased. The value of flexibility strength of B4C-CeB6/Al composites was 409.47 MPa, which was improved nearly 39.32% compared with that of monolithic boron carbide; the value of fracture toughness was 6.58 MPa.m1/2, which was improved nearly 78.80% compared with that of monolithic boron carbide. The flexibility strength and the fracture toughness of B4C-CeB6/Al composites were greatly improved for two major reasons. Firstly the crack deflection caused by the residual stress resulted from the difference in thermal expansion coefficient between B4C and CeB6 was the main toughening mechanisms. Secondly the ductility of aluminum was manifested in B4C-CeB6/Al composites.