基于Krging的压射机构铸造工艺参数多目标优化

Multi-objective Optimization of Injection Mechanism and Casting Process Parameters Based on the Krging Model

压射机构是挤压铸造设备中进行充填成形的重要装置,其组件的配合间隙决定了充型过程中的精度和稳定性。为了使压射过程中组件的配合间隙变化最小,针对初始间隙值、浇注温度等压射机构与工艺的关键参数,以间隙率和温差为目标,提出了一种基于Kriging元模型的多目标优化方法。结果表明,所建Kriging元模型精度高于0.97;最优工艺参数:铸件浇注温度为701℃,压室预热温度为338℃,压室壁厚为16 mm,初始间隙为0.1061 mm,压射速度为56 mm/s。优化后,间隙率减小了10%,换热温差减小了49%,充型过程更加稳定。

Injection mechanism is important for filling and forming in squeeze casting equipment.The fit clearance of its components greatly affects the accuracy and stability in the injection process.To minimize the change of fitting clearance during injection,a multi-objective optimization method based on the Kriging metamodel was proposed which taken into account for the clearance rate and temperature difference as the objectives,and considered the key parameters of the injection mechanism and process such as initial clearance and pouring temperature.The results show that the accuracy of Kriging metamodel is higher than 0.97.Meanwhile,the optimized process parameters were presented as follows:casting pouring temperature of 701℃,shot-sleeve preheating temperature of 338℃,shot-sleeve wall thickness of 16 mm,initial clearance of 0.1061 mm and injection velocity of 56 mm/s,where the clearance rate is reduced by 10%and the heat transfer temperature difference is reduced by 49%after optimization.In addition,the filling process is more stable.