Influence of process parameters on quality of aluminum High Pressure Die Casting (HPDC) parts manufactured with a novel vertical chambered machine
Against the background of increasing demands on resource efficiency, the moulding manufacturing processes with their great design freedom and the associated load-adapted geometries plays a crucial role. In particular, the combination of aluminum alloys in die casting and thermoplastics in injection molding processes offers the advantage of a lightweight design [1] that also offers good recyclability [2]. A new type of combined process is used for optimized process control, in particular using a temperature control cascade for efficient waste heat utilization, which combines the die casting, stamping and injection moulding processes. In addition, the novel process of vertical die casting with two movable pistons is developed and prototyped, which promises both high efficiency and a low-porosity and therefore high-quality material structure [3].
The material structure and the associated mechanical properties of the structural components are determined by a number of influencing factors [4]. To estimate a process window for the newly developed process, a simulation model is set up using ESI's ProCast software. This study provides information on the key aspects of the simulation model and technical limitations. For example, the process control with two moving pistons or the holding pressure phase can only be modeled with the software to a limited extent according to the state of the art. Strategies are therefore presented and critically discussed in order to develop a workaround for these problems. Finally, based on several simulations with different influencing variables such as melt or mould temperature, a parameter study is carried out according to a fractional factorial design in order to identify the main influencing variables and quantify their sensitivities.
Based on these findings, critical parameter combinations during production and their negative effects on the quality, for example the amount of air entrainment, are identified. Finally, the simulation results are compared with the casting images of manufactured parts of the vertical chambered HPDC machine. These insights enable understanding of the reasons for defects detected by optical and X-ray examinations. This makes it possible to significantly reduce development times and the experimental effort involved in running die casting processes and to produce high-quality components with resource-saving energy consumption.
References:
[1]Messer, Patrick, A. Bulinger, U. Vroomen, and A. Bührig-Polaczek. ‘Multi-Component High Pressure Die Casting (M-HPDC): Temperature Influence on the Bond Strength of Metal-Plastic-Hybrids Manufactured by M-HPDC’. In Light Metals 2019, edited by Corleen Chesonis, 423–28. The Minerals, Metals & Materials Series. Cham: Springer International Publishing, 2019. https://doi.org/10.1007/978-3-030-05864-7_54 .
[2]D’Errico, Fabrizio, G. Perricone, and M. Alemani. ‘A Novel Flexible SSM and HPDC Equipment to Process Secondary Aluminium Alloys for Decarbonising Lightweight Parts in Automotive Sector’. In Light Metals 2019, edited by Corleen Chesonis, 1475–83. The Minerals, Metals & Materials Series. Cham: Springer International Publishing, 2019. https://doi.org/10.1007/978-3-030-05864-7_185 .
[3]Druckguss Service Deutschland GmbH. ‘Presentation DuoCast Series by DSD’. Accessed 26 March 2024. https://www.dgs-hl.de/duo-cast-serie.html.
[4]Dos Santos, Silvano Leal, R. Altobelli Antunes, and S. Ferreira Santos. ‘Influence of Injection Temperature and Pressure on the Microstructure, Mechanical and Corrosion Properties of a AlSiCu Alloy Processed by HPDC’. Materials & Design 88 (December 2015): 1071–81. https://doi.org/10.1016/j.matdes.2015.09.095 .