TiB2颗粒增强2024Al材料薄板的性能与高速粒子撞击损伤

Properties and hypervelocity impact damage of TiB_2 particles reinforced 2024Al aluminum alloy thin targets

利用二级轻气炮、光学显微镜、扫描电镜和透射电镜等手段研究了TiB2／2024Al复合材料薄板在2．5km／s速度下，粒子直径为0．8—2．0mm撞击时的宏观、微观损伤特征与损伤机理．结果表明：在高速粒子撞击作用下，TiB2／Al复合材料薄板的主要损伤特征为背面崩落.随着增强相含量的增加，TiB2／Al复合材料抗粒子侵彻穿深能力提高，抗崩落能力的下降，导致靶板正面坑宽和坑深尺寸不断减小，而背面崩落损伤区直径不断增加．TiB2／2024A1复合材料的微观损伤模式以TiB2颗粒的破碎为主．分析认为，在高速撞击作用下，TiB2颗粒内部位错大量堆积而萌生微裂纹，微裂纹扩展导致裂纹源形成．

In the paper, the impact resistance ability and macro-damage characteristic of TiB2/2024AI composites thin tar- gets were researched by two-stage light gas gun （at a velocity of 2.5 km/s） , split Hopkinson pressure bar （SHPB） , optical microscope （ OM ） , scanning electron microscope（ SEM ） , transmission electron microscope （ TEM ） and high-resolution electron microscopy （HREM）. Results showed that the TiB2/2024AI composites showed good penetration resistance and significant spalling damage. With TiB2 particle content increasing, the penetration depth decreased and the diameter of spalling area on the back surface increased. Analysis presented that the micro-cracks were formed inner TiB2 particls under high speed impact.