Effect Of Metal Powder On Minimum Ignition Energy And Flame Propagation Law Of HMX Dust Cloud

As one of the best elementary explosive with comprehensive performances,HMX is widely used in military,aerospace and other industries.Therefore,it has value to study the effect of metal on fatalness of HMX.In this paper,using 1.2L Hartmann tube system and high-speed camera,etc,select and use three kinds of metal powders,Al,Ti and Zr,which have been studied and applied in energetic materials,research their effect on the minimum ignition energy and the law of flame propagation of HMX dust cloud.The research indicates:(1)HMX dust of 8μm and 14.57μm particle size,in the range of 500-1000g/m~3mass concentration,the minimum ignition energy of dust cloud decrease with the increase of mass concentration;When the mass concentration is 800g/m~3,the minimum ignition energy of HMX dust cloud with particle size of 14.57μm decrease first and then increase with the increase of air humidity;And when the air humidity is 30%,the minimum ignition energy of the dust cloud is the smallest,and the value is 50.30mJ.(2)Adding a small amount of Al,Ti,Zr metal powder under a certain mass concentration condition can reduce the minimum ignition energy of HMX dust cloud;When the mass fraction of aluminum powder is 20%,the minimum ignition energy of the mixed dust cloud is the smallest,and the value is 32.62mJ;When the mass fraction of metal powder is 20%,the minimum ignition energy reduction effect of HMX dust cloud is Al>Ti>Zr in order from large to small.(3)The maximum flame height and maximum propagation speed of HMX dust cloud with average particle size of 8μm,14.57μm,35.24μm and 60μm increase with the increase of dust cloud mass concentration;The maximum height of dust cloud flame at each mass concentration increase first and then decrease with the increase of dust particle size.The maximum propagation speed of dust cloud flame at each mass concentration increase first and then decrease with the increase of dust particle size.Under the condition of high concentration,the maximum propagation speed decreases with the increase of the particle size.In addition,the test results were analyzed by variance;The data showed that the mass concentration and particle size of the dust cloud had a highly significant and significant effect on the maximum flame height,respectively;And they both had a highly significant effect on the maximum propagation velocity of the flame.(4)In the case of certain conditions of mass concentration and dust particle size,the maximum flame height and propagation speed of HMX dust cloud added with Al increase and then decrease with the increase of Al mass fraction;When the mass fraction of Al is 30%,the maximum flame height and propagation speed are the largest,their values are 508.457mm and65.361m/s,respectively;The maximum propagation speed of HMX dust cloud flame with different mass fractions of Ti was significantly reduced.When the mass fraction of Ti was40%,the maximum flame height of dust cloud was reduced,too;The maximum flame height and propagation speed of the HMX dust cloud added with Zr increase and then decrease with the increase of Zr mass fraction.When the Zr mass fraction was 30%,the maximum flame height and propagation speed were the largest.The values are 500.912mm and 67.041m/s,respectively;Among the three metal powders,Al and Zr have a certain promoting effect on the flame propagation of HMX dust cloud,while Ti has no such effect.