爆速对纳米铝粉爆炸烧结性能的影响

摘要

为了掌握纳米金属粉烧结成型技术,将纳米铝粉置于改良设计的可泄压式爆炸烧结装置中,得到了密实度达98%以上的纳米铝棒.通过改变铵梯炸药和木粉的比例调节炸药的爆速,研究了不同爆速下烧结铝棒的性能.利用金相显微镜观察烧结棒的微观结构,并对烧结棒的密实度、硬度等性能进行测量.结果表明:通过降低爆速可以减小马赫孔的产生,但爆速过低,会导致烧结棒的密实度和硬度等性能降低;当采用爆速为2158m/s的炸药时,可制得无马赫孔、高硬度、高密实度、晶粒细小的均质烧结棒.%An aluminum bar with a dense degree of over 98% was fabricated using nano-aluminum powders in an improved sintering device capable of pressure relief to study the sintering molding of nanometer metal powders.First,the performance of the sintering aluminum bar at different detonation velocities were obtained by adjusting the ratio of the ammonium nitrate explosive to the wood powder.Then the microstructures of the aluminum bars were observed using metallurgical microscopy,and such mechanical properties as the density and hardness were measured.The results show that the Mach-hole can be reduced by reducing the detonation velocity.However,the excessively low detonation velocity decreases the mechanical properties such as the density and the hardness.Moreover,the sintering aluminum bar that is free from any Mach-hole,of higher hardness,higher dense degree and finer grain size can be fabricated from nano-aluminum powers whose detonation velocity reaches 2 158m/s.