碳化硼复合陶瓷增强增韧研究进展

Research progress on strengthening and toughening of boron carbide composite ceramics

碳化硼(B_(4)C)复合陶瓷因高强度而被广泛应用于装甲和刀具等。但因烧结性能差,断裂韧性低,限制了广泛应用。综述了氧化物、碳化物、硼化物及其他增强相对B_(4)C复合陶瓷力学性能的影响,探讨了降低B_(4)C烧结温度,提高其强度和韧性的机制和途径。其中,过渡金属硼化物(如TiB_(2)等)通过颗粒增韧,热膨胀系数的差异导致的裂纹偏转、桥接,增强相的拔出等机制可以大幅度提高B_(4)C复合陶瓷的强度和韧性,是目前最有效的增强增韧途径。

Boron carbide(B_(4)C)composite ceramics are widely used in armor and cutting tools due to their high strength.However,the poor sintering performance and low fracture toughness have limited their extended applications.The effects of oxides,carbides,borides and other reinforcement phases on the mechanical properties of B_(4)C composite ceramics were reviewed.The mechanisms and ways to reduce the sintering temperature and improve the strength and toughness of B_(4)C were explored.Among them,transition metal borides(such as TiB 2)could substantially improve the strength and toughness of B_(4)C composite ceramics through mechanisms such as particle toughening,crack deflection and bridging due to differences in the thermal expansion coefficient,and pullout of the reinforced phase,which is currently the most effective way for strengthening and toughening.