Chieh-Fong Lin, Chia-Yu Kao, Chen-Ming Chen, Imang Eko Saputro, Intan Mardiono, Ming-Hsiu Ho, Cheng-Fu Huang, Sheng-Chan Lee, Yiin-Kuen Fuh
Defects in high-pressure die casting (HPDC) significantly impact product lifespan, casting quality, and manufacturing costs. This study investigates defects in the initial HPDC process of AlSi12 aluminum alloy cover plates for automotive hydraulic systems. The goal is to propose process schemes that eliminate defects, enhance quality, and improve mechanical properties. Three casting schemes were examined, combining three plunger velocities and two mechanical boosters, with a focus on their practical feasibility. A retained melt modulus model was used for numerical analysis to identify regions prone to shrinkage porosity. Strategies were developed to minimize the percentage of elements with shrinkage porosity while optimizing elongation and ultimate tensile strength through tensile tests and analyzing grain size via microstructure analysis. Numerical simulations were employed to design and refine the proposed schemes, correlating plunger velocities and mechanical boosting with experimentally validated product quality and mechanical properties. In Case 3, shrinkage porosity was reduced from 0.59 to 0.41% (30.5% improvement), elongation increased from 6.03 to 9.13% (51.4% improvement), ultimate tensile strength rose from 256.7 to 299.09 MPa (16.5% improvement), and average grain size decreased from 25.62 to 18.76 µm (26.8% improvement). Case 3 was validated by X-ray, demonstrating its effectiveness. Although minor shrinkage porosity persisted, helium leak tests confirmed no impact on the cover plate’s quality. This study highlights the significant role of numerical simulation in designing HPDC process schemes, providing a robust approach to improving product quality and mechanical performance. © American Foundry Society 2025.
Department of Mechanical Engineering, National Central University, Taoyuan City, 320317, Taiwan; GlobalTek Fabrication Co., Ltd., Xinwu Factory, Taoyuan City, 327001, Taiwan; Industrial Engineering Study Program, Institut Teknologi Sumatera, Terusan Ryacudu Street, South Lampung, 35365, Indonesia