In manufacturing, precision and efficiency are paramount. One tool that has revolutionized the way we approach casting processes is casting simulation. Gone are the days of trial and error, as this technology allows us to predict, analyze, and optimize every aspect of the casting process with unprecedented accuracy.
Here, Product Marketing Manager Mark Vroljik talks to Loic Calba, casting expert and Product Manager for ESI’s ProCAST casting solution to discuss the key advantages of using casting simulation and explore what insights it can provide.
[Loic Calba] The casting process involves pouring molten metal into a mold cavity, allowing it to solidify and take the shape of the mold, followed by post-processing operations such as demolding and degating, cleaning, machining, and finishing.
The casting process is widely utilized across various industries, including automotive, aerospace, heavy machinery and marine. In automotive and aerospace industries, casting is extensively used for manufacturing engine components, transmission parts, and structural components due to its ability to produce complex shapes with high strength-to-weight ratios. In heavy machinery, casting is employed for producing very large parts with sizes of often several meters, such as pumps, housings and ingots. Additionally, the marine industry relies on casting for manufacturing ship components, propellers, and offshore structures.
The major casting processes include sand casting, investment casting, and die casting. Sand casting involves creating molds from sand mixed with binders, which are then packed around a pattern and molten metal is poured into the cavity. This process is versatile and cost-effective, suitable for producing large and complex parts in low to medium volumes. Investment casting, also known as lost-wax casting, utilizes a wax pattern coated with ceramic slurry to form the mold, which is then melted away, leaving a cavity for pouring molten metal. This process is ideal for intricate and high-precision parts with excellent surface finish, making it suitable for aerospace, automotive, and medical industries. Die casting involves injecting molten metal into a steel mold cavity under high pressure, producing parts with tight tolerances and smooth surfaces, commonly used for high-volume production of components with complex geometries, such as automotive parts and consumer electronics.
[LC] When selecting between high-pressure die casting, investment casting, or sand casting, considerations are made based on factors such as complexity of the component, production volume, material properties, and surface finish requirements. High-pressure die casting is preferred for high-volume production of intricate and geometrically complex parts with tight tolerances, typically made from non-ferrous metals like aluminum, zinc, or magnesium. Investment casting, also known as precision casting, is chosen for producing highly detailed and near-net-shape components with excellent surface finish and dimensional accuracy, particularly for low to medium production volumes or when casting materials have high melting points, such as stainless steel, titanium, or superalloys. Sand casting is ideal for producing large and heavy components in low to medium volumes, offering versatility for casting various metals and alloys, including ferrous and non-ferrous materials, while allowing for cost-effective tooling and setup for prototypes or short production runs.
[LC] Mega (also referred to as Giga) castings are large-scale, single-piece castings produced using advanced casting techniques, typically for automotive structural components such as vehicle frames or battery enclosures. These castings are characterized by their massive size and intricate geometries, which are often challenging to manufacture using traditional methods. In the automotive industry, giga castings are increasingly utilized to reduce weight, improve structural integrity, and streamline assembly processes. By consolidating multiple smaller components into a single giga casting, automakers can achieve significant weight savings while enhancing overall vehicle rigidity and crashworthiness. Additionally, mega castings offer benefits such as reduced manufacturing complexity, lower assembly costs, and improved scalability, making them an attractive solution for electric vehicles (EVs) and other advanced automotive applications.
[LC] Producing mega castings poses several challenges compared to standard casted components due to their massive size, intricate geometries, and stringent quality requirements. One major challenge is ensuring uniform solidification and cooling rates throughout the casting to prevent defects such as shrinkage, porosity, and hot spots. Additionally, handling and transporting mega castings present logistical challenges due to their size and weight, requiring specialized equipment and facilities. Maintaining dimensional accuracy and structural integrity over large spans is also crucial, necessitating precise control of casting parameters and post-casting processes.
[LC] We have a simple to use and efficient guided workflow for any of the 3 major casting processes, as well as for many of their variants. Casting simulation offers several key advantages in the manufacturing process, providing engineers with detailed insights into the casting process before physical prototypes are produced. With casting simulation, engineers can accurately predict and analyze various aspects of the casting process, including mold filling, solidification, cooling rates, and the formation of defects such as porosity, shrinkage, and inclusions. By simulating these processes, engineers can optimize casting designs, minimize defects, and improve the overall quality of cast components. Additionally, casting simulation enables the exploration of different materials, process parameters, and geometries, leading to cost savings, reduced development time, and enhanced efficiency in the manufacturing process.
Due to the complexity of mega castings, simulation is absolutely key in getting the process right and to ensure you achieve the desired properties and performance without running into endless physical iteration loops with associated long lead times and high costs.
Regarding the simulation particularities of these parts, ESI ProCAST is especially well-suited for modeling these types of parts as the solution is excellently scalable up to 32 cores, which is an almost mandatory pre-requisite to get acceptable turnaround times for these huge parts. Also, our solution offers not only functionality for the standard filling and solidification phases, but considers all aspects of the high-pressure die casting process: from die heating and spraying, till part ejection, cutting and cooling. Even after-casting processes can be considered, like various heat treatment processes, and ultimately also include the cast manufacturing properties in performance tests, as after all, you don’t want these parts to become heavily damaged during a crash event.
A third important aspect is that it is absolutely key to predict accurately the required closing force needed to cast the part correctly. As these parts are huge, the presses required to produce them are extreme, and require very high closing forces to withstand the internal pressures during the casting cycles. To accurately predict the minimum required closing force, it is absolutely mandatory to include the casting fluid during filling and solidification, and the possible air entrapment, as this drastically impacts the required local pressures in the die, and could, if not well taken care of during the simulations, result in non-manufacturable parts on the selected machine. As ESI ProCAST is a 2-phase solution, meaning considering air and fluid interactions, this aspect is well covered.
[LC] In principle if the customer is already familiar with high pressure die casting simulations, they should be able to setup a standard filling and solidification simulation without additional training. There are few additional complexities to master though, as the model size and the number of objects is quite huge as well. This requires a clean structure for object naming and ordering, and attention needs to be paid to correctly meshing the components
What normally is the more ‘tricky’ part is the correct modeling to get accurate stresses in the part, as in the end these are the origins of the distortions after demolding and during cooling to room temperature. You can easily imagine that small changes in stress distribution can have a non-negligible influence on the final distortion magnitudes for such large parts. Fortunately, thanks to the finite element foundation of our stress solver, this part is well taken care of and even for these large parts distortions can be predicted within few millimeter tolerances!
But just to ensure that our customers get the right results for these costly parts, we normally guide them closely through this process and during the first trials guide them step-by-step to develop the required expertise, and to gain insights and trust in modeling the process for these complex parts.
We recently hosted a ‘MegaCasting: Engineering the Future of Automotive Manufacturing!’ webinar which provides more insights into megacasting technology.
To watch the recording click here
After completing his masters at the faculty of Aerospace Engineering at the Delft University of Technology, Netherlands, Mark Vrolijk started his career with ESI in June of 2000 as a technical support engineer for ESI’s Virtual Manufacturing Portfolio. His specialty focus was on the sheet metal forming processes. After holding various positions in the sheet metal forming trade, including technical product manager, product marketing manager, and strategy manager, he is now currently working as a senior product marketing manager for all ESI’s Smart Manufacturing solutions.