【摘要】 大型机匣作为航空航天领域的核心承力部件，其变壁厚结构导致蜡模注射成形过程中易产生翘曲缺陷，严重影响产品质量与安全性。本课题以小型阶梯件为研究对象模拟机匣变壁厚几何结构，以注射压力、注射时间和保压时间为关键工艺参数，采用L₉（3³）正交试验设计，结合数值模拟技术，研究了各参数对变壁厚区域翘曲量的影响规律。通过极差分析与方差分析，各工艺参数对翘曲影响的主次顺序为：注射压力>保压时间>注射时间，并确定最佳工艺参数组合：注射压力3 MPa、注射时间3 s、保压时间60 s。通过实际注射试验与数值模拟翘曲分布云图对比发现，在薄壁以及壁厚突变区翘曲趋势高度一致，验证了数值模拟模型的可靠性及最优参数的有效性。研究结果对具有阶梯件壁厚特征如大型机匣的蜡模注射工艺优化和精密铸件成形质量提升具有重要参考价值。更多还原

【Abstract】 The large-sized casing,as a core load-bearing component in the aerospace field,is prone to generate warpage defects during the wax pattern injection forming process due to its variable wall thickness structures,severely affecting product quality and safety.This project uses a small stepped component as a study object to simulate the geometrical structure of a casing with variable wall thicknesses.Taking injection pressure,injection time and pressure holding time as the key parameters,applying an L₉（3³） orthogonal experimental design,and combining with numerical simulation technology,the influence rules of these parameters on the warpage amounts in the variable wall thickness regions have been investigated.Through range analysis and variance analysis,the primary and secondary orders of influences of the process parameters on the warpages were determined as:injection pressure>pressure holding time>injection time,and the optimal combination of process parameters was confirmed as:injection pressure of 3 MPa,injection time of 3 s and pressure holding time of 60 s.Through comparing actual wax pattern injection experiments with numerical simulation warpage distribution contour maps,it was found that a high consistent warpage trends in the thin-wall areas and the regions with abrupt thickness changes were obtained,verifying the reliability of the numerical simulation model and the effectiveness of the optimal parameters.The results provide valuable insights for the optimization of wax pattern injection processes and the improvement of forming quality in precision castings with the wall thickness features of stepped component such as the large-sized casings.更多还原