中文摘要：

研究电爆炸丝演化过程对于理解丝爆物理机制和纳米粉体生成机制具有重要意义。该文采用马赫曾德（Mach-Zehnder）激光干涉法对金属钛丝在空气中的电爆炸过程进行诊断，环境气体气压为适宜纳米粉体制备的气压，范围为几-几百kPa。诊断结果表明，钛丝存在两种电爆炸模式：多次喷发模式和一次喷发模式。环境气体气压决定了钛丝的电爆炸模式，当环境气压较低（如为10kPa左右）时，因钛丝沿面击穿过早终止了钛丝的焦耳加热过程，钛丝中沉积能量远低于钛丝完全汽化所需能量，钛丝不能一次性完全汽化，其材料将采用多次喷发模式汽化；随着环境气压升高，如接近或高于50kPa时，钛丝沿面击穿时刻推迟，从而使钛丝中沉积能量接近甚至高于完全汽化所需能量，钛丝材料将一次性喷发完毕。

英文摘要：

With a Mach-Zehnder interferometer, the evolution of titanium wire explosion in ambient gas for nano- powder production was investigated to better understand the mechanisms of wire explosion and nano-powder growth. We find that there are two exploding modes of titanium wire explosion under different gas pressures： the multi-burst mode and the one-burst mode. When the air pressure is equal to or below 10 kPa, the early flashover discharge along the exploding wire will cease the Joule heating of wire and result in lower deposition energy less than the energy of whole wire vaporization, and the wire can not explode totally within one single burst. However, when the air pressure exceeds 50 kPa, the moment of flashover discharge along the exploding wire will be delayed, the deposition energy into the wire will be close to or higher than the energy of the whole wire vaporization, and the wire will explode within one single burst.