The application of computer aided engineering (CAE) has become a trend in manufacture industry due to its great efficiency and reliability. In casting industries, numerical modelling of the casting process based on CAE has replaced traditional trial-and-error R&D procedures in many aspects. With advanced parallel computing techniques and numerous calculation models, the fluid flow, heat transfer, solidification and defect formation behaviours under different casting conditions may be examined in detail. Based on this idea, component design and the optimization of casting parameters may be carried out to produce products for subsequent microstructural and mechanical characterization. In this way, a direct link between process condition, casting quality, and cast mechanical properties may be established in a manner that is practical, economical and energy efficient for such processes as gravity die casting, high pressure die casting (HPDC) and continuous casting.

In this work, the entire HPDC process, including die heating, thermal die cycling, shot sleeve pre-filling, slow shot/fast shot injection, die filling/solidification as well as intensification, is simulated for an Al-Si alloy using the casting simulation package ProCAST. The interfacial heat transfer coefficients between melt and die wall/shot sleeve are adjusted according to thermal couple measurements and infrared imaging of the die surface temperature distribution. Based on this complete numerical model, the HPDC process may be optimized using the following methodology: 1) the optimum thermal die cycle number is determined after which the dynamic steady state of die temperature is obtained to guarantee relatively sound casting quality. 2) The piston shot profile is adjusted to reduce defect formation during injection. In the meantime, tensile bars are cast using the optimized piston shot profile and the mechanical properties (yield strength, ultimate tensile strength and elongation) are tested to assess the effectiveness of the computer simulation. Results show that the mechanical properties are improved with the optimized process parameters, providing further evidence that CAE could help in the optimization of HPDC processes.

由于计算机辅助工程（CAE）的高效率和可靠性，其应用已成为制造业的趋势。在铸造行业中，基于CAE的铸造过程的数值建模已在许多方面取代了传统的试验与错误R＆D程序。利用先进的并行计算技术和众多的计算模型，可以详细检查不同铸造条件下的流体流动，传热，凝固和缺陷形成行为。基于这种想法，可以进行零件设计和铸造参数的优化，以生产用于后续的微结构和机械表征的产品。以此方式，可以以实用的方式建立工艺条件，铸造质量和铸造机械性能之间的直接联系，

在这项工作中，使用铸件模拟了铝硅合金的整个HPDC过程，包括模头加热，热模头循环，喷丸套预填充，慢喷/快喷注射，模头填充/凝固以及强化。模拟包ProCAST。根据热偶测量和模具表面温度分布的红外成像，可以调节熔体与模具壁/喷丸套筒之间的界面传热系数。基于此完整的数值模型，可以使用以下方法优化HPDC工艺：1）确定最佳的热模循环次数，然后获得模头温度的动态稳态，以保证相对良好的铸造质量。2）调整活塞喷丸轮廓以减少注射过程中的缺陷形成。同时，使用优化的活塞压射轮廓铸造拉伸棒，并测试机械性能（屈服强度，极限拉伸强度和伸长率）以评估计算机模拟的有效性。结果表明，通过优化工艺参数可以改善机械性能，从而进一步证明CAE可以帮助优化HPDC工艺。