Sand Casting

The use of simulations allows verifying and studying the effectiveness of the technology and observing the internal processes occurring in the casting.

Shrinkage cavities

Residual stresses

Macro and microporosity

Cracks (hot and cold)

Deformations and warping

Metal structure

Modeling enables the avoidance of the defect correction stage, reduces the costs of readjusting equipment in terms of both time and materials, and minimizes the number of trial castings when launching new products into production.

Products
Sand casting modeling in PoligonSoft

Cost and Time Reduction

Save significant costs in materials and labor, in addition to reducing product development time.

Improve Quality and Precision

Prevent and correct casting defects, such as porosity, air inclusions, or solidification issues.

Process and Design Optimization

Experiment with different variables of the casting process to find the most efficient configuration.

Process Optimization

The process of optimizing the casting technology for a helicopter cabin frame is demonstrated. The primary goal is to reduce the cost of technology by minimizing the use of expensive thermal insulating materials and simplifying the complexity of mold assembly.
Helicopter Window Frame

Magnesium Alloy - ML5pch

Mold - Cold-Setting Mixtures to Alpha-Set

Isothermal Insulators - FOSECO

Pouring Temperature - 760°C

Casting Block Mass - 55.3 kg

Casting Mass - 9.8 kg

Helicopter Window Frame produced by a company within the Russian Helicopters holding

Defective Technology

The previous technology allows for obtaining a casting suitable for use; however, the cost, labor intensity, and quantity of defective products are high.

Analysis indicated that the technology is not stable enough.

The casting solidifies almost simultaneously with the feeder system. This means that with minimal changes in the technology parameters (such as the temperature of the molten metal), shrinkage porosity can form in the body of the casting.

Helicopter Window Frame Porosity
Helicopter Window Frame Porosity

Modification 1

gating system

To achieve a defect-free casting and decrease costs, a change was made in the design of the gating system. The vertical feeders were replaced by a single lateral feeder without thermal insulation. The concept of the central feeder remained unchanged.

Porosity levels are within the established limits for manufacturing.

Porosity levels
High levels of residual stresses and plastic deformations

High levels of residual stresses and plastic deformations are observed.

High levels of residual stresses and plastic deformations

Result

The calculations made allowed the identification of the cause of cracks at the intersection of the casting with the gating and feeder system.

An improved version has been developed with a lower level of residual stresses, which allows for defect-free castings.

The developed design has been implemented and is currently used in helicopter manufacturing.

gating and feeder system
Intensity of Plastic Deformations

Intensity of Plastic Deformations

Porosity Analysis

Manufacture of an experimental batch of "Stator Ring" castings at the SIEMENS company.
Stator Ring

The first casting made according to the company's technology contained defects:

Incomplete filling of the teeth on the inner surface.

Porosity in the area of the feeders.

Stator Ring

Defective Technology

Simulation in PoligonSoft helped to understand the causes of the defects...

Defective Technology
Sprue
Exothermic
Feeders
Cross-section of the temperature field in the porosity area shows the formation of un-fed thermal nodes.

Cross-section of the temperature field in the porosity area shows the formation of un-fed hot spot.

The porosity exit zones to the surface detected

The porosity exit zones to the surface detected in the simulation coincide with the experimental result.

Result

... modifying the technology to achieve a casting suitable for use.

Result

Insulator (new)

Iron chillers
(new)

Chromite rod
(new)

Exothermic feeder
(new size)

Exothermic feeder to eliminate the area of macro and microporosity (new)

Final Result - a defect-free piece

defect-free piece

Prevention of Hot Cracks

Simulation of the casting process of an industrial valve body is shown. The main objective is to verify the reliability of our hot crack prediction system.
Prevention of Hot Cracks

Alloy - Steel 20GL

Mold - Clay-bonded sand

Exothermic feeders - Foseco Kalminex

Pouring temperature - 1600°C

Holding ladle parameters

Holding ladle parameters

Mold Filling

Solidification

Flow velocity field
Temperature distribution
Solidification dynamics

Porosity

Porosity of 0.7% and above
Porosity of 0.7% and above
Porosity of 0.8% and above
Porosity of 0.8% and above
Porosity of 1% and above
Porosity of 1% and above

Deformation

Deformation
Deformation

Result

The mathematical model of stress and deformation state of the casting developed by "PoligonSoft" is capable of predicting with high probability the formation of hot and cold cracks.

The simulation of most modern casting technologies requires considering the contact interaction between the casting and the mold, as this interaction is often the cause of crack formation.

The ability to predict crack formation at the design stage significantly reduces the time and expenses required to adjust and optimize the technological process.

Hot Crack Indicator
Hot Crack Indicator
Verification of results

Verification of results