基于不同Ta10W渗镀层厚度的火炮身管热力耦合数值分析

Thermo-mechanical coupling numerical analysis of cannon barrels with different thicknesses of Ta10W coating

采用双辉等离子渗金属技术于火炮身管内膛渗镀抗烧蚀涂层,是延长身管武器寿命的重要手段之一。为探究Ta10W渗镀层对火炮发射传热过程以及应力分布的影响规律,该文以某125 mm口径火炮为研究对象,通过热力耦合数值分析法,根据内弹道时期火药高温高压燃气的动态变化过程定义热力载荷以及边界,从而获得在高速热流工况下,Ta10W渗镀层厚度为0.04~0.10 mm时,火炮身管的传热变化过程以及应力分布特点。结果表明:随着渗镀层厚度的增加,弹后炮尾的最高温度呈下降趋势,不同厚度产生的应力差值在身管中段会大于身管尾部,同时在炮尾的涂层与基体结合处产生应力集中,0.04 mm、0.07 mm和0.10 mm厚度Ta10W层的应力最大值分别为891.4 MPa、884.3 MPa和879.1 MPa。

It is one of the important means to prolong the barrel weapon life by using double glow plasma surface alloying technique to permeate anti-ablation coating.To investigate the influence of Ta10W coating on the heat transfer process and stress distribution of a cannon during the firing,and to reveal the impact of different coating thicknesses on the cannon barrel,this article established a three-dimensional numerical model of a 125 mm caliber cannon using the finite element method.Based on the thermo-mechanical coupling finite element model of the barrel,the thermal load and boundaries were defined according to the dynamic changes of high-temperature and high-pressure combustion gas during the interior ballistics phase.The heat transfer model and stress field distribution model of 0.04~0.10 mm Ta10W thickness under high-speed thermal flow conditions were obtained.The computational simulation results show that with the increasing coating thickness,the highest temperature at the rear of the gun after firing shows a decreasing trend.The difference in stress generated by different thicknesses is greater in the middle section of the barrel than at the rear of the barrel.Additionally,stress concentration occurs at the interface between the coating and the substrate at the breech.The maximum stress values of the 0.04 mm,0.07 mm,and 0.10 mm thickness coatings are 891.4 MPa,884.3 MPa,and 879.1 MPa,respectively.