大长径比熔铸装药热芯棒凝固工艺优化仿真

为提高大长径比战斗部的熔铸装药质量,采用有限元仿真方法建立了三维装药模型,对熔铸装药过程进行数值模拟。通过分析传统铸装和热芯棒工艺铸装的仿真结果,结合缩孔形成原因和传统热芯棒工艺对装药质量的改善机理,设计出一种多层次优化温度控制的热芯棒,并对改良热芯棒工艺铸装过程进行数值模拟,预测热芯棒改良工艺对装药质量的影响。结果表明:传统热芯棒铸装工艺无法改变药柱径向凝固顺序,在药室宽大处仍然会出现缩孔缩松的疵病,而改良热芯棒工艺通过改善药柱凝固顺序,可以预防缩孔缩松出现,达到了预期要求。

Process of Improved Hot Mandrel for Large Length-Diameter Ratio Warhead Melting Cast

In order to improve melt-casting charge quality of the warhead with a large length-diameter ratio,a three-dimensional charge model was established by means of the finite element simulation method,and numerical simulation on the melt-casting charge process was carried out,including traditional casting and hot mandrel process casting.Then combined with the shrinkage principle and mechanism of the traditional hot mandrel process to improve charge quality,a multi-layered hot mandrel with optimized temperature controlling was proposed and its casting process simulation was undertaken to predict how it exerts effects on the charge quality.The results show that the radial solidification order of the grains can’t be changed and shrinkage as well as porosity would appear at the wider area of the explosive room in the traditional hot mandrel casting process.However,the defects of shrinkage and porosity can be avoided by changing the radial solidification order in the improved hot mandrel process,which just corresponds to our expectation.