Research On The Combustion Characteristics Of Zirconium Powder And Its Application In Solid Propellants

The new generation of high-performance SRM is the power plant mainly used in advanced missiles weapon.The research on new solid composite propellants is one of the important ways to promote the development of SRM technology.Based on the high-performance SRM applications,taking the high-density propellant metal additive Zr as the research object.The physicochemical properties of Zr powder,the ignition combustion of zirconium powder and the ignition combustion of zirconium-containing propellant were studied.The feasibility of Zr powder in composite propellant was initially explored.Firstly,experimental research on the physical and chemical properties of zirconium powder was carried out.The experimental results show that the Zr powder specimen has irregular particle shape,mainly containing Zr element,and a small amount of O and Hf.The main phase is metal Zr.Oxidation process of Zr powder undergoes a process of slow oxidation,accelerated oxidation,violent oxidation and reaction equilibrium.The activation energy Ea of micronsized zirconium powder is 175.83kJ/mol,and the pre exponential factor A is1.91×10⁸s^-1.The non-isothermal oxidation process accords with the random nucleation and subsequent growth model functionG???=[-ln?1-??]^?.Secondly,by studying the influence of Zr powder particle size and oxygen concentration on the ignition and combustion characteristics,it is found that the combustion of zirconium powder can be divided into four stages:light-off,intense combustion,stable combustion and flame extinction.Parameters such as zirconium particle size and oxygen concentration have an important influence on the ignition and combustion properties of zirconium powder.Reducing the particle size of zirconium powder and increasing the oxygen concentration are beneficial to shorten the ignition delay time and combustion time,improve the combustion temperature and combustion intensity.Further,the ignition and combustion performance of zirconium powder are improved.The simulation results of CHEMKIN software show that the oxygen concentration increases,the combustion time decreases,and the combustion temperature increases.The theoretical calculations and experimental results confirm each other.Again,using CEA to analyze the energy properties of three different zirconium-containing propellants,it suggests that the addition of zirconium powder to the propellant can significantly improve the energy properties of the propellant,especially the density specific impulse.The density specific impulse of butylated hydroxy propellant reaches the maximum when 45%zirconium powder is added.The density specific impulse of NEPE propellant and high energy azide propellant continue to increase with the increase of zirconium powder content.In addition,the specific impulse of high-energy azide propellant has an increasing trend with the increase of zirconium powder in the range of0%³%.Finally,the ignition combustion experiment of zirconium-containing propellant was carried out.It is found that the parameters such as zirconium powder content,zrconium powder particle size and pressure have an important influence on the ignition and combustion performance of zirconium-containing propellant.Increasing the zirconium powder content,reducing the particle size of the zirconium powder,and increasing the pressure are all beneficial to shorten the ignition delay time and burning time,and improve the ignition and combustion performance of the propellant.As the content of zirconium powder increases,and the content of Al powder decreases,the particle size of the propellant combustion product decreases.That is to say,the size of the combustion agglomerate of the Al powder particles in the propellant is larger than that of the zirconium powder combustion agglomerate.Through the above work was carried out,it suggests that the addition of zirconium powder to the propellant can significantly improve the ignition and combustion performance of the propellant,improving the energy characteristics and increasing the density specific impulse of the propellant,and ameliorate the agglomerate level of the propellant combustion products.