添加TiB_(2)对石墨烯改性B_(4)C陶瓷基复合材料抗弹性能的影响

Effect of TiB_(2) Addition on Ballistic Properties of Graphene Modified B_(4)C Ceramic Matrix Composites

为支撑新型轻质防弹装甲材料的研发和优化,以添加和未添加增韧相TiB_(2)的两种石墨烯改性碳化硼(B_(4)C)陶瓷复合材料为研究对象,研究其在12.7 mm口径穿甲弹侵彻下的失效机理。利用维氏硬度计、三点弯曲法和单边切口梁法获得两种陶瓷基复合材料的维氏硬度、弯曲强度和断裂韧性3个准静态力学性能参数,通过残余穿深试验研究两种复合材料在12.7 mm口径穿甲弹正侵彻下的抗侵彻能力,并采用防护系数进行定量表征。结合铝合金背板和陶瓷碎块的宏观损伤形貌,利用扫描电镜进行微观断口分析,研究陶瓷在弹头侵彻下的失效机理、增韧相TiB_(2)以及石墨烯的强化机制。结果表明:TiB_(2)的加入可以提高石墨烯改性B_(4)C陶瓷的各项性能,相较不含TiB_(2)的石墨烯改性B_(4)C陶瓷,含质量分数14%TiB_(2)改性B_(4)C陶瓷的维氏硬度、弯曲强度和断裂韧性分别提高了19.66%、24.06%和19.70%,在12.7 mm口径穿甲弹弹头750 m/s速度侵彻下的防护性能提高15.11%;对于石墨烯改性B_(4)C陶瓷,TiB_(2)的加入与石墨烯的促进作用使B_(4)C陶瓷变为多种破坏吸能模式,表现出更优异的抗破碎性,是其抗侵彻性能等提高的主要原因。

The failure mechanisms of graphene modified B_(4)C composites with and without TiB_(2) under the penetration of 12.7 mm armor-piercing projectiles were studied for the development and optimization of new lightweight materials for bulletproof armor.The Vickers hardness,bending strength and fracture toughness of the two ceramic matrix composites were obtained by using Vickers hardness tester,three-point bending method and single edge notched beam method.The anti-penetration performances of the two composites penetrated by 12.7 mm armor-piercing projectiles are studied through the residual penetration depth experiment,which are quantitatively characterized by the protection coefficient.A scanning electron microscope(SEM)was used to analyze the macroscopic damage morphologies of 7075 aluminum alloy back-plates and ceramic fragments to study the failure mechanism of ceramic and the strengthening mechanisms of TiB_(2) and graphene.Experimental results show that the addition of TiB_(2) can enhance the properties of graphene modified boron carbide ceramics.Compared with the material without TiB_(2),the Vickers hardness,bending strength and fracture toughness of the material containing 14wt.%TiB_(2) are increased by 19.66%,24.06%and 19.70%,respectively,and its anti-penetration performance is increased by 15.11%under the penetration of 12.7 mm armor-piercing projectiles at 750 m/s.It is shown that the B_(4)C ceramic matrix composite exhibits a variety of energy absorption modes and a better crushing resistance due to the addition of TiB_(2) and the strengthening effect of graphene,which is the main reason for the improvement of anti-penetration performance.