Influence of powder size distribution and powder density distribution on the final shape of PM HIP-ed components

该项目的目标是开发一种模拟工具，用于更精确地预测HIP生产的部件的最终形状，以取代传统的试错法。改进了多孔粉末的本构方程，该方程同时依赖于塑性和粘塑性变形，并在有限元软件ABAQUS中实现。该项目的一个重要重点是更好地了解粉末粒度分布和不均匀密度分布对HIP部件最终形状的影响。仿真模型考虑了上述因素。该方法被证明使用气体雾化不锈钢粉末的HIP致密化。仿真模型所需的所有参数都是通过实验确定的。此外，在HIP容器中的不均匀的温度分布的预测形状的准确性的影响进行了详细的研究。此外，目前的研究表明，关节囊设计和关节囊厚度对HIP期间组件的变形有显著影响。通过有针对性地使用胶囊几何形状对最终部件形状的影响，将通过采用新方法和几何优化来优化HIP前胶囊的形状和尺寸。准确的预测模型可以与优化工具一起使用，以便在HIP之前优化胶囊的形状和尺寸。预计新方法的使用允许在HIP后生产具有严格尺寸公差的净形部件。更新提案的主要目标是1。继续执行原计划中所述的剩余工作包。特别是剩余的材料参数的实验测定，模型验证的模拟和实验需要进行。2.分析了粉末粒度分布、初始粉末分布不均匀和热等静压容器中的温度梯度对热等静压生产的部件最终形状的影响。3.使用数值优化的胶囊设计制造净形部件。

The objective of the project is to develop a simulation tool for a more precise prediction of the final shape of components produced by HIP in order to replace the conventional Trial and Error method. The constitutive equation of porous powder, which depends on both plastic and viscoplastic deformation, is improved and implemented in a finite element code in ABAQUS. An important focus of this project is to gain an improved understanding of the influence of powder size distribution and inhomogeneous density distribution on the final shape of HIP-ed components. The simulation model accounts for the above mentioned factors. The methodology is demonstrated using HIP densification of a gas atomized stainless steel powder. All parameters needed for the simulation model are experimentally determined. In addition, the effect of inhomogeneous temperature distribution in the HIP vessel on the accuracy of the predicted shape is investigated in detail. Furthermore, current studies show that capsule design and capsule thickness significantly contribute to the distortion of components during HIP. Through targeted use of the effect of capsule geometry on the final component shape, the shape and size of the capsule before HIP will be optimized by employing the new methodology together with geometrical optimization. An accurate prediction model can be used together with an optimization tool in order to optimize the shape and size of the capsule before HIP. It is expected that use of the new methodology allows for the production of net-shape components with tight dimensional tolerances after HIP. The main objectives of the renewal proposal are 1. Continuation of the remaining work packages as described in the original plan. In particular remaining experimental determination of material parameters, simulations and experiments for model verification need to be performed. 2. Analysis of the influence of the powder size distribution, an inhomogeneous initial powder distribution and a temperature gradient in the HIP vessel on the final shape of components produced by HIP. 3. Manufacturing of net-shaped components using numerically optimized capsule design.