Thermodynamics Of Removing Copper From 152mm Gun Under Powder Firing Condition

The copper in the bore of the Artillery affects the stability and firing accuracy of projectile launch.For a long time,lead has a good effect of removing copper,but the lead is easy to be corroded and discharged into the environment,which is a serious threat to human health and life.Therefore,there is an urgent need to develop a lead substitute to improve the service life of artillery,storage of ammunition and shooting accuracy,and to protect the environment which human beings depend.For this reason,this dissertation takes double aromatic-3 charge and 152 mm artillery as the research object,using the MATLAB software write the internal ballistic program to calculate the firing chamber internal pressure and temperature,combining with the REAL software and alloy distillation thermodynamics theory to lead,tin,bismuth,copper removal of thermodynamics research.The main research contents are as follows:(1)According to the basic theory of artillery classical interior ballistics,the mathematical model of the internal ballistics of simple powder shape single charge is established.Based on the fourth-order Runge-Kutta method,the internal trajectory program is programmed by MATLAB software to obtain the bore pressure,the chamber temperature with time and projectile Itinerary of the law of change,using the bore pressure and chamber temperature to simulate the gunnery environment.The simulation results show that the gun bore temperature of 152 mm artillery reaches the gunpowder explosion temperature of 2598.3K at the moment of gunpowder firing,and reaches the maximum chamber pressure of 224.7MPa when the projectile moves 4.5ms.The projectile reached the muzzle after 11.2ms,the muzzle temperature was 2039.1K and the muzzle pressure was 95.9MPa.Compared with the test data,the relative error of the maximum chamber pressure is less than 6% and the relative error of the explosive temperature is less than 1%.(2)Through to the artillery bore environmental simulation,using the REAL software are calculated respectively under the condition of artillery firing,in 8.135 kg the aromatic-3 propellant charge loading quality 2% copper and 2% copper and 2% tin,lead,2% copper and 2% 2% copper and 2% bismuth in chemical composition and phase composition of combustion products.Calculation results show that: when the temperature is 2039.1 K,pressure is 95.90 MPa,after add lead,tin,bismuth,the remaining liquid copper quality is 155.83 g,the quality of the remaining liquid lead,tin,bismuth,respectively is 58.22 g,151.65 g and 32.95 g.Gaseous copper is mainly in the form of Cu,CuOH,Cu2 and CuH,and the gasification of copper is mainly caused by temperature and reaction of gunpowder combustion products.(3)Because REAL software has flaws and can not reflect the process of metal alloying,the calculation result can not truly reflect the effect of removing copper from artillery.Therefore,a new idea of removing copper from artillery is proposed.The artillery is mainly divided into three parts,Of the role of the copper into copper vapor removed,the second part is the reaction of copper and fired charge combustion products into the vapor of copper compounds removed,the third part is the residual liquid in the bore of copper and copper removal of liquid metal The formation of the environment within the alloy,the alloy under high temperature and pressure distillation volatilization into gas,after the projectile out of the muzzle,the role of the pressure in the chamber removed.Based on the copper removal assumption,the remaining liquid copper and the alloys formed of lead,tin and bismuth are 73% Cu-Pb,50% Cu-Sn and 82% Cu-Bi.(4)The activity coefficients of Cu-Pb,Cu-Sn and Cu-Bi binary alloys at 2039.1K and the volatilization coefficient under the condition of gun firing were calculated by using the Miedema alloy thermal model and REAL calculation results.On this basis,the gas-liquid equilibrium compositions phase diagram of Cu-Pb,Cu-Sn and Cu-Bi binary alloy systems were calculated.According to the gas-liquid equilibrium compositions phase diagram,the volatilization masses of 155.83 g copper are respectively 6.23 g,64.36 g and 4.42 g when distilled with 73% Cu-Pb,50% Cu-Sn and 82% Cu-Bi binary alloys Metal,it is clear that Sn is a more effective than the copper artillery in addition to copper material,copper removal effect of Bi is less than the copper removal effect of Pb.