精密鑄造鑄件中的缺陷會降低鑄件質量並增加製造成本，不可避免地縮短使用壽命。本文對收縮孔隙率進行了數值計算，採用RMM模型來分析高度可能的區域。通過比較了各類澆鑄設計方案之鑄件品質（收縮孔隙率），且顧及可加工性的實際可行性，並研擬透過調整保溫棉覆蓋方案來減低鑄件缺陷生成率。這項研究的目的是確定具有最低PES（具有收縮孔隙缺陷的元素的百分比）且在工業上具可行性之方案，同時以最低的加工成本進行鑄造，並增加材料得料率。模擬中採用虛擬熱力學傳感器來指示裝配的不同組樹之澆鑄系統對冷卻梯度和凝固方向的影響。選擇精密鑄造條件的最佳參數來在熔模鑄造鑄造廠中實際製造閥殼，並以實物之品質比對模擬之結果證明可信度。根據ASTM E2660之規範檢測之X光照片的結果幾乎沒有發現鑄造中通常會發生的有害缺陷，從而相應地驗證了提出方案的有效性。並以熱像儀蒐集之數據回推到模擬結果，驗證澆注品質和殼模溫度對缺陷生成的相關性。;Defects in investment casting will inevitably reduce the lifetime and degrade the casting quality and increase manufacturing costs, accordingly. In particular, shrinkage porosity was numerically conducted, and a retained melt modulus model was implemented to analyze highly probable regions. The proposed casting schemes of gating designs are compared by quality of casting (shrinkage porosity) and practical feasibility in terms of small hole drilling machinability. The purpose of this study was to determine the feasible plan with the lowest PES (percentage of elements with shrinkage porosity) while promoting the near net shape casting with minimum machining cost and increase material usage. Virtual thermo-dynamical sensors were adopted in the simulations to indicate the impacts of different gating systems of pattern assembly on the cooling gradient and direction of solidification. The best-case scenario of investment casting conditions was chosen to fabricate valve housing in an investment casting foundry. Experimental results of X-ray image according to ASTM E2660 standard differentiated nearly none of the pernicious defects that typically occurred with proposed casting, authenticating the proposed scheme′s efficacy accordingly. In addition, use the data collected by the thermal camera to push back to the simulation results to verify the correlation between the filling form quality and the shell mold temperature of the shell mold on the generation of defects.
