CAE simulation analysis - Zhejiang Ningbo Hexin focus on low pressure casting, gravity casting, die casting mold manufacturing, aluminum casting plant

What is the casting (high-pressure die casting, gravity casting, low-pressure casting) on the use of CAE simulation simulation analysis

In die casting, low-pressure casting and gravity casting (including sand/metal type), CAE simulation is used as the core digital tool for coupled numerical simulation of the whole casting process by constructing a three-dimensional model covering the mold, casting and sprue system. Its common core analysis module includes:Charging process simulation(Analyze liquid metal flow patterns, predict cold segregation and gas wrapping),Solidification process simulation(analyzing temperature field and solidification sequence, predicting shrinkage) andStress/deformation simulation(Prediction of thermal stresses, residual stresses and deformations). For process characterizationDie casting CAE focuses on high-speed mold filling and air roll analysis, mold heat balance and cooling optimization.；Low-pressure casting CAE focuses on precise control of air pressure field, sequential solidification and shrinkage simulation.；Gravity casting CAE focusing on natural flow regime under gravity, solidification paths and riser make-up efficiency assessmentThe fundamental role is to scientifically predict defects and optimize process parameters and mold design. The fundamental role is to scientifically predict defects, optimize process parameters and mold design to significantly improve casting quality, shorten development cycles and reduce trial and error costs.

temperature simulationCAE Simulation Aluminum Casting Temperature Simulation

Aluminum casting temperature simulation analysis is a method of dynamic simulation of aluminum liquid flow, solidification and temperature field changes in the casting process through computer numerical simulation technology. It is based on the principles of thermodynamics and fluid dynamics, constructs a three-dimensional model of the casting-mold system, and quantitatively analyzes the aluminum liquid filling speed, solidification gradient, thermal joint distribution and potential shrinkage defects, so as to optimize the design of the pouring system, control the cooling conditions, and realize the digital prediction of the casting process and quality improvement.

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Filling flow simulationCAE Simulation of Aluminum Casting Filling Flow Simulation

Aluminum casting filling flow simulation analysis is a key means of high-precision numerical simulation of the flow state of aluminum liquid during the filling process in the casting system using Computational Fluid Dynamics (CFD) technology. By establishing a complete three-dimensional model including gate, runner and cavity, the analysis dynamically simulates the free surface flow of liquid aluminum, air-rolling phenomenon, turbulence development and temperature change, and accurately reveals the formation mechanism and location of defects such as fluid separation, cold segregation, air wrapping and oxidized slag which may occur in the filling process, so as to provide a scientific visual basis for optimizing the layout of the pouring system, controlling the filling speed and improving the internal quality of the castings. and decision-making support.

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Barometric Pressure Simulation AnalysisCAE Simulation of Aluminum Casting Volume Gas Simulation Analysis

Aluminum casting gas simulation analysis is the use of multiphase flow computational fluid dynamics (CFD) technology, specifically to track and analyze the casting mold filling process of air or cavity gas by the liquid aluminum involved in the formation of porosity defects and stagnation of the fine simulation process. It is through the construction of “liquid aluminum - gas” two-phase or “liquid aluminum - gas - oxide” multiphase model, accurate simulation of liquid aluminum turbulence front of the splash, convergence, vortex and other complex flow patterns, dynamically capture the gas involved in the fragmentation, polymerization and uplift and escape behavior, so as to Accurately predict the size, location and distribution probability of the gas holes inside the casting. This analysis is a key digital tool for optimizing casting system design (e.g., avoiding turbulence), setting reasonable venting schemes and process parameters to minimize harmful gas entrainment, and improving casting metallurgical quality and service performance.

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Shrinkage simulationCAE simulation of aluminum casting shrinkage simulation

Aluminum casting shrinkage simulation analysis is a key simulation technology based on the principles of heat transfer and solidification shrinkage to predict the void defects formed in the casting during solidification due to liquid shrinkage and solidification shrinkage without sufficient liquid metal shrinkage. The analysis is performed by constructing an accurate 3D model of the casting-gate system, coupling the temperature field, solid-phase rate field and liquid flow field, and dynamically tracking the solidification sequence and the formation of isolated liquid-phase zones, so as to accurately predict the dimensions, morphology, and spatial distribution of volumetric defects such as shrinkage holes and shrinkage loosening. The core purpose is to scientifically evaluate and optimize the riser position and size, cold iron arrangement and pouring process parameters to achieve active control of the solidification path and shrinkage channel, and ultimately obtain a dense and sound internal organization of the casting.

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CAE Simulation and Analysis for Casting

He Xin Molding incorporated this into the mold development phaseCAE (Computer-Aided Engineering) Casting Simulation Analysis...by constructing a 3D numerical model that encompasses the mold, castings, and gating system, a multi-physics coupled simulation of the entire casting process is performed. The core value of CAE simulation lies inPredict defects and optimize process parameters before mold machining, reducing the 4 to 6 rounds of trial molding and mold modification required by the traditional trial-and-error method to Within 2 rounds, the development cycle for a single mold has been shortened by more than 30%, and trial mold costs have been reduced by approximately 40%.

He Xin's CAE simulation capabilities cover three processes: high-pressure die casting, low-pressure casting, and gravity casting. Leveraging leading simulation platforms such as ProCAST, MAGMASOFT, Flow-3D, and AnyCasting, the company can performMolding Flow Simulation, Solidification and Cooling Analysis, Gas Trapping Prediction, Cavitation and Porosity Assessment, Thermal Stress and Deformation CalculationsFive core analysis modules. Simulation results directly guide the design of the gating system, the layout of cooling channels, venting strategies, and the setting of process parameters, facilitating a shift in mold development from a "trial-and-error" approach to a "data-driven" one.

Simulation Positioning:CAE simulation does not replace trial molding; rather, it shifts the purpose of trial molding from "verifying the design" to "confirming the process window." He Xin’s experience shows that thorough simulation analysis can reduce the number of mold trial iterations from the industry average of 4 to 6 rounds to fewer than 2 rounds; however, mold trials are still ultimately required to confirm fine-tuning of process parameters under actual production conditions.

Four Core Simulation and Analysis Modules

CAE Simulation for CastingFilling → Solidification → Defects → StressFour physical processes are carried out, with data coupling between the various modules, collectively forming a comprehensive digital verification system for the casting process:

Filling Flow Simulation

Based on CFD (Computational Fluid Dynamics), this method solves the Navier-Stokes equations to simulate the flow path, filling velocity distribution, and free-surface morphology of molten metal within the gating system and mold cavity. It can predict filling defects such as cold shuts, underfill, and flow marks, and outputs data on filling time, flow velocity fields, and temperature fields to guide the optimization of gate location and cross-sectional area.

Solidification and Cooling Analysis

Couples the solution of the heat transfer equation with the release of latent heat of solidification to calculate the temperature-time curves, solidification sequence, and solid fraction distribution for various regions of the casting. Identify isolated liquid zones and hot spots, predict the tendency for shrinkage cavities and porosity, and quantify the probability of defects using the Niyama criterion or the solid fraction gradient method to guide the layout of risers and chill blocks.

Gas Inclusion and Oxidation-Induced Slag Inclusion

The multiphase flow (VOF method) is used to track the interface between molten aluminum and gas, simulating the entrainment, fragmentation, coalescence, and rise of gas during the mold filling process. Quantitative outputs—including the location of entrained gas, gas volume fraction, and retention probability—guide the optimization of vent channel and vent plug layouts, as well as adjustments to the pouring rate curve.

Stress and Strain

By coupling the temperature field with the mechanical field, this method calculates the thermal stress distribution, residual stress levels, and deformation of castings during solidification and cooling. It predicts the risk of hot cracking (based on the Hot Cracking Sensitivity Index, HCS) and dimensional deviations, providing a basis for designing mold counter-deformation compensation and establishing heat treatment processes.

Key Focus Areas of CAE Simulation for Three Casting Processes

The mechanisms of mold filling and defect patterns vary significantly across different casting processes, and the focus and key criteria of CAE simulations differ accordingly:

Die Casting CAE Simulation

Filling Rate50–100 m/s (internal gate)

Filling Time0.01–0.2 s

Key AnalysisHigh-Speed Air Swirl + Thermal Equilibrium

Recommended SoftwareFlow-3D / MAGMASOFT

Key CriteriaResidual Gas Volume Fraction

Grid RequirementsThin-walled areas with ≥3 layers

The core challenge of die-casting CAE lies inHigh-Speed Turbulent Filling ModelAccurate simulation. Simulation Focus: ① Filling sequence—ensuring synchronized filling of all gates to prevent cold shuts caused by premature local solidification; ② Gas tracking—quantitatively analyzing gas escape paths within the cavity to evaluate the effectiveness of overflow channels and vent channels; ③ Mold thermal equilibrium—simulate the mold temperature distribution after continuous production (15–30 cycles), optimize cooling channel parameters, and stabilize the mold temperature within the 180–220°C process window.

Low-Pressure Die Casting CAE Simulation

Filling Rate0.05–0.5 m/s

Filling Pressure0.02–0.08 MPa

Key AnalysisSequential Solidification + Shrinkage Compensation Efficiency

Recommended SoftwareProCAST / MAGMASOFT

Key CriteriaNiyama's Rule / Solid-Phase Ratio Gradient

Grid RequirementsIncreased Density in the Gate and Shrinkage Compensation Zones

The core of low-pressure casting CAE lies inSequential Solidification and Pressure FeedingCoupling analysis. Simulation focus: ① Temperature field evolution—simulate the temperature distribution at the riser and gate to ensure that the feed channels remain unobstructed throughout the solidification process; ② Prediction of shrinkage cavities and porosity—Quantifying the tendency for porosity using the Niyama criterion (threshold value < 0.8–1.0 √K·s/mm) to optimize holding pressure (0.1–0.3 MPa) and holding time; ③ Stability of filling—Controlling the molten metal front velocity to ≤0.5 m/s to prevent the entrainment of the oxide layer caused by free-surface turbulence.

Gravity Casting CAE Simulation

Rechargeable PowerGravitational Potential Energy

Pouring Temperature680–750°C (A356)

Key AnalysisGating System + Risers Efficiency

Recommended SoftwareAnyCasting / ProCAST

Key CriteriaSolidification Sequence + Effective Distance of the Sprue

Grid RequirementsLocal Densification of the Spout Neck

The focus of CAE for gravity casting is onGeometric Parameters of the Gating Systemtogether withEfficiency of Shrinkage Compensation via RisersOptimization. Simulation Focus: ① Flow patterns in the gating system—simulate the flow velocity distribution in the transverse and vertical runners to avoid turbulence and air entrapment, ensuring smooth filling; ② Shrinkage compensation via risers—verify through solidification simulation whether the riser positions and dimensions can cover all hot spots, and calculate the effective shrinkage compensation distance (typically 3–5 times the wall thickness); ③ Core gas generation—For resin-bonded cores, consider the impact of gas generation on filling and solidification, and optimize the venting channels.

CAE Simulation Software Toolchain

Based on different casting processes and analysis requirements, He Xin has selected several specialized CAE simulation software packages, each with its own focus, which complement one another:

Software Name	Core Advantages	Applicable Processes	Key Features	Grid Type
MAGMASOFT	High accuracy in solidification and stress analysis, with precise simulation of the mold temperature field	Die Casting, Low-Pressure Casting, Gravity Casting	Multi-cycle thermal equilibrium analysis, microstructure prediction	FDM (Finite Difference Method)
ProCAST	Strong multiphysics coupling capabilities and accurate radiation and heat transfer calculations	Low-pressure, gravity (including sand molds)	Hot Cracking Prediction, Grain Structure Simulation, and Deformation Compensation	FEM (Finite Element Method)
Flow-3D	Highest accuracy in free-surface tracking; leading high-speed filling simulation	Die casting	TruVOF Method, Quantitative Analysis of Volatile Gases, Oxidation Film Tracking	FVM + FAVOR
AnyCasting	Easy to use, fast computation, and suitable for rapid iteration	Gravity, Low Pressure	Gate Optimization Wizard, Parallel Comparison of Multiple Solutions	FDM (Finite Difference Method)

Standard Process for CAE Simulation and Analysis

He Xin's CAE simulations follow standardizedFive-Step Analysis Process, to ensure the reproducibility of simulation results and their value as engineering guidance:

Geometric Preprocessing

Import the 3D models of the casting and mold, extract the fluid and solid domains for the gating system, casting, and mold, perform meshing (ensuring ≥3 mesh layers for thin-walled parts), and set the interfacial heat transfer coefficient (casting-mold: 500–2000 W/m²·K).

Materials and Boundary Conditions

Select an aluminum alloy grade (A356 / A380 / ZL101, etc.), set the thermal properties (liquidus temperature, solidus temperature, latent heat, viscosity curve), and configure the pouring temperature, mold preheating temperature, and filling rate/pressure curve.

Solve the problem

Launch the multiphysics coupling solver to sequentially calculate the filling flow field, temperature field, and solidification process. Typical solution times: 2–4 hours for die-casting filling analysis and 4–8 hours for low-pressure casting solidification analysis (depending on the number of mesh elements and hardware configuration).

Post-processing of Results

Visualize the filling sequence, temperature field, solidification rate distribution, locations of shrinkage cavities and porosity, volume fraction of entrapped gas, and stress distribution. Extract key criteria values (Niyama number, residual gas volume fraction, and thermal cracking susceptibility index) to generate defect prediction reports.

Iterative Process Optimization

Adjust the pouring system parameters (gate area, overflow channel position), cooling parameters (coolant flow rate, coolant temperature), or process parameters (pouring temperature, filling rate) based on the simulation results, and rerun the simulation to verify the changes until the predicted defects meet quality requirements.

Key Simulation Parameters and Boundary Conditions

The accuracy of CAE simulations depends heavily onThe Rationality of Boundary Condition Setting. The following are the key simulation parameters calibrated by He Xin based on actual production data to ensure that deviations between the simulation results and the physical test mold are kept within an acceptable range:

Parameter Categories	Parameter Name	Typical Values / Range	Impact on Simulation Accuracy
Thermal Properties	A356 Liquidus Temperature	615°C	Factors Affecting the Determination of the Onset of Setting
Thermal Properties	A356 Solidus Line Temperature	555°C	Factors Affecting the Setting Point and the Closure Time of the Shrinkage Channels
Thermal Properties	Latent Heat of Solidification (A356)	389 kJ/kg	Effects on Setting Time and Temperature Field Calculations
Interface	Heat Transfer Coefficient for Castings and Molds	500–2,000 W/m²·K	Directly affects the cooling rate and solidification sequence
Interface	Molds—Cooling Water Heat Transfer Coefficient	3,000–8,000 W/m²·K	Factors Affecting the Thermal Equilibrium of a Mold
arts and crafts	Pouring Temperature (A356)	700–740°C	Factors Affecting Filling Capacity and Solidification Time
arts and crafts	Mold Preheating Temperature	180–250°C (die casting) / 150–200°C (low-pressure)	Factors Affecting Filling Completeness and Solidification Rate
arts and crafts	Die-Casting Filling Rate	50–100 m/s (internal gate)	Factors Affecting Air Volume and Surface Quality
arts and crafts	Low-Pressure Hold Pressure	0.1–0.3 MPa	Factors Affecting Shrinkage Compensation Efficiency and the Tendency for Shrinkage Voids
Criteria	Niyama Threshold	< 0.8–1.0 √K·s/mm	Shrinkage determination threshold; values below this threshold indicate a risk of shrinkage
Criteria	Residual Gas Volume Fraction	< 2% (Safety Component)	Quantitative Measures of Porosity Defects
Criteria	Heat Cracking Sensitivity Index (HCS)	< 1.0 (Low Risk)	Thermal Cracking Risk Assessment Thresholds

Frequently Asked Questions About CAE Simulation Technology

Q: How much do CAE simulation results differ from actual mold trial results? Can they be trusted?

He Xin’s practical experience shows that, provided the boundary conditions are set reasonably (with the interfacial heat transfer coefficient calibrated using production data), CAE simulations can achieve an accuracy rate of over 85% in predicting the location of shrinkage cavities and porosity, and an accuracy rate of over 90% in predicting filling defects (cold shuts and underfill). The main sources of deviation are: ① The interfacial heat transfer coefficient varies dynamically with mold temperature and coating condition, but is typically assumed to be constant in simulations; ② The actual viscosity of molten aluminum is influenced by gas content and oxide inclusions, causing it to deviate from theoretical values; ③ Operational fluctuations during production (pouring temperature ±10°C, mold preheating uniformity) are difficult to fully replicate in simulations. Therefore, He Xin adopted a strategy of "simulation to guide direction, trial molding to confirm boundaries"—using simulation to screen options and optimize design directions, and trial molding for final verification and fine-tuning of process parameters.

Q: Can CAE simulation be used to predict porosity in die-cast parts? Why does the simulation show no porosity when there is actually some?

CAE simulation of die-casting porosity presents inherent challenges: die-casting filling speeds can reach 50–100 m/s, and the process of gas evacuation from the mold cavity involves complex turbulent and atomization behavior. Simulation faces the following limitations: ① Insufficient mesh resolution: The number of mesh elements in thin-walled regions (1–3 mm) is limited by computational resources, making it difficult to analyze the formation process of micron-scale porosity; ② Release agent volatilization: It is difficult to accurately quantify the volume of gas produced when the release agent instantly vaporizes upon contact with high-temperature molten aluminum; ③ Vacuum level simulation: The vacuum level within the mold cavity in vacuum die casting changes dynamically, making it difficult to precisely define the simulation boundary conditions. Therefore, He Xin’s die casting CAE simulation is primarily used to evaluateTrends in Porosity Distribution and Relative Severity(which area has more pores), rather than precisely predicting the location and size of individual pores. Ultimately, pore control still requires a combination of vacuum system commissioning and process parameter optimization.

Q: How long does a complete CAE simulation and analysis take? What is the cost?

The simulation cycle depends on the complexity of the casting and the depth of the analysis: ① For simple structural components (such as brackets and housings), a filling and solidification analysis requires 1–2 days for preprocessing, 4–8 hours for solving, and 0.5 days for postprocessing, for a total of approximately 2–3 workdays; ② For complex structural components (such as cylinder heads and manifolds), a full analysis (filling + solidification + stress + entrapped gas) requires 2–3 days for preprocessing, 12–24 hours for solving, and 1 day for postprocessing, totaling approximately 4–5 business days. He Xin’s CAE simulation is offered as part of its mold design services,No separate charge— Simulation analysis costs are included in the mold design and development fees. Customers receive a complete simulation analysis report during the mold development phase and do not incur any additional simulation costs.

Q: How complex of castings can He Xin's simulation capabilities handle? Is there anything it can't do?

He Xin's current CAE simulation capabilities coverWeight per item: 0.05–50 kgAluminum alloy castings, covering common product types such as structural parts, housings, wheel hubs, and manifolds. Simulation limitations exist in the following scenarios: ① Ultra-thin-walled parts (wall thickness < 0.8 mm)—insufficient mesh resolution reduces the accuracy of filling behavior predictions; it is recommended to validate results through physical mold trials; ② Composite casting with multiple inserts—the interface behavior between inserts and molten aluminum (e.g., encapsulation rate, interfacial bond strength) is difficult to accurately assess using conventional CAE simulation; ③ Semi-solid casting (rheological casting/thixotropic casting)—The non-Newtonian rheological behavior of semi-solid slurries requires specialized rheological models, which Hexin does not currently support. If your product falls under any of the above special scenarios, we recommend contacting us in advance so that Hexin can assess whether supplementary verification can be provided through external collaboration or specialized testing.

Need support for CAE simulation and analysis in casting?

Send us your product drawings and manufacturing requirements, and Hexin’s engineers will conduct CAE simulation analysis concurrently during the mold design phase and provide a detailed defect prediction report and recommendations for process optimization—the simulation costs are included in the mold development service at no additional charge.

Submit your drawings to receive a simulation analysis proposal →