Research On The Influence Of Hygroscopicity On The Performance Of Typical Ignition Powder Containing Metallic Powder

The Metal powder-containing ignition powder has the advantages of strong ignition ability,safety and insensitiveness,and good manufacturability.It is widely used as the basic charge of various ignition devices such as propellant,propellant,explosive and pyrotechnic powder.However,the nature of metal powder is relatively active,and it is easy to be damp and cause failure or performance degradation.Three typical ignition powders containing metal powder: magnesium tellurium dioxide(MTD),aluminum potassium perchloratealuminum(APP)and zirconium potassium perchlorate(ZPP)have been studied.The ignition powder in the three states after the high temperature and high humidity test,hygroscopicity test and the non-moisture state are compared,and the effect of moisture absorption and moisture on the performance of the ignition powder is obtained.Firstly,the moisture absorption test was carried out on the three ignition powders according to the "determination of hygroscopicity" and the hygroscopicity was analyzed.The results show that the hygroscopicity of MTD is significantly,and the APP and ZPP hardly hygroscopicity.The order of the hygroscopicity of the three groups of agents is as follows: MTD> APP> ZPP.The high temperature and high humidity test was carried out on the three ignition powders,and they formed three states with the ignition powders after the hygroscopicity test and the without moisture.Scanning electron microscopy(SEM),X-ray diffraction(XRD)and differential scanning calorimeter analysis(DSC)are used to analyze the three ignition powders in three states.The results show that the physical properties and chemical composition of APP and ZPP are hardly affected by humid environment,but the influence of humid environment on MTD is very obvious.According to the composition analysis,the magnesium powder in the MTD reacts with the moisture in the environment to form magnesium hydroxide.On the basis of interior ballistics,MATLAB/Simulink is used to compile a constant-volume internal ballistic program to simulate and predict the P-t curves of the three ignition powders.The results show that the peak pressure and action time of APP and ZPP are relatively close,the peak pressure is 10-12 MPa,and the peak pressure of MTD is 5.5-6 MPa.The P-t curves of three kinds of ignition powders(three states of each kind)is tested with a closed explosive device.The test results show that,after passing through a humid environment,the pressure loss of the three ignition powders is in the order of MTD>ZPP>APP.After the MTD undergoes high temperature,high humidity and hygroscopicity tests,the pressure drops by 89%?94%,the pressure of ZPP drops by5.6%?11.4%,and the pressure change of APP is 0.2%?5%.The hygroscopicity analysis,physical and chemical analysis and output performance of three typical metal powder-containing ignition powders are analyzed.As a result,the surface MTD will be severely affected by the humid environment,and strict sealing measures must be taken to avoid moisture.This study reveals the sensitivity of ignition powders containing metal powder to humid environments and provides guidance for the application of these three types of agents.