梯度飞片材料的波阻抗分布设计与优化

Design and optimization of wave impedance distribution for flyer materials

建立起了梯度飞片击靶的理论模型 ,对具有不同波阻抗分布特征的W Mo Ti体系梯度飞片的击靶过程进行了数值模拟计算 .结果表明 ,梯度飞片对靶产生的压缩是逐步进行的 ,靶板的自由面速度也是逐渐提高的 ,准等熵压缩过程的加载速率远低于传统冲击压缩 .为获得较好的准等熵压缩效果 ,梯度飞片的波阻抗分布应遵循随厚度变化的二次至三次幂函数关系 ,并且靶板厚度必须与梯度飞片的击靶速度等相匹配 .

Flyers with wave impedance gradient can be regarded as a new kind of functionally graded material, which has come to show great potential for the application in dynamic high-pressure technology. In the present paper, a theoretical model of generating quasi-isentropic compression via the W-Mo-Ti system flyer was established, and the numerical simulation has been carried out. The results show that the design for flyers with graded wave impedance should conform to the parabolic or cubic function relationship of the change in the thickness. The thickness of target and the impact velocity should also be well controlled for creating a better quasi-isentropic compressive wave profile.