3D finite element temperature field modelling for direct laser fabrication
3D finite element temperature field modelling for direct laser fabrication
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DOI：
10.1007/s00170-008-1785-x
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发表时间：
2009-08
期刊：
影响因子：
--
通讯作者：
Jia Yang;Fude Wang
中科院分区：
文献类型：
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作者：
Jia Yang;Fude Wang
为了描述激光直接制造（DLF）过程中的热动力学行为，提出了一种基于全局模型和子模型模式的三维有限元温度场模型。通过扫描路径规划，全局模型反映了零件在整个热历史中的热传导特性。模型中设计了接触对和间隙单元，考虑了温度和孔隙率对热传导的影响，以解释粉末到固体的本征转变。此外，在模型中还采用了元素去除和再激活技术，体现了材料的逐步增加特征。利用ABAQUS开发的激光修复实例，验证了该模型的热历史，并估算了纯镍热物性非线性行为对温度分布的影响。采用考虑固液相变的热物理参数，熔池温度比不考虑固液相变参数时的熔池温度高。
In order to describe the thermal dynamics behaviour in direct laser fabrication (DLF), a 3D finite element temperature field model is proposed to be built/developed based on global model and sub-model pattern. The global model exhibits the heat conduction characteristics of parts in the whole thermal history according to scanning path planning. Contact pairs and gap elements, which consider the effect of the temperature and porosity-dependent thermal conduction, are designed in the model to explain powder-to-solid intrinsic transition. In addition, the elements removed and reactivated technology is applied in the model so as to embody the material stepwise increasing feature. A laser-repairing case developed by ABAQUS demonstrates the global model’s thermal history, and the influence of non-linear behaviour of thermal properties in pure nickel on the temperature distribution is estimated as well. Adopting the thermal physical parameters with solid–liquid phase change will make the melted pool temperature higher than that where the solid–liquid phase change parameters are not considered.