The production of castings is always a challenge, and not everything always goes as planned. There are several factors that, when not managed, compromise the quality of one, or even a batch of parts that come out defective. A delivery defect is the deviation in quality or condition of an actual casting compared to an ideal product.
The Simcenter Star-CCM+ has models that accurately predict the most common defects that can compromise the quality of castings.
Common defects are:
Porosity
Oxides
Misruns
Gas Inclusion
Porosity
Micro porosity:
Criteria functions as empirical models to assess micro shrinkage
Niyama Criterion
Dimensionless Niyama Criterion
Require manual validation for different alloys against real casting
Macro porosity
For pure thermal simulations based on density based volume deficits in isolated liquid metal pockets
High fidelity macro shrinkage prediction for fully coupled simulations based on pressure drop in isolated liquid metal pockets allows to include buoyancy effects
Oxides
Passive scalar based oxide prediction model:
Accumulates the time the metal phase is exposed to air
User can modify the underlying oxide accumulation law to include effects such as the amount of oixidizable amount of metal
The model does not influence the flow field but the effect of an oxide film on the flow may be included by oxide thickness based viscosities
Evaluating the filling front:
The filling front will usually transport the most of the oxides and dirt
By tracking the progress of the filling front and its final resting place, the oxide contamination can be estimated
Misruns
Concurrent solving of flow and solidification:
The solidification of metal and its effects on the filling of the mold is calculated concurrently to the actual flow
Mushy zone for technical alloys:
Modeling effects of growth and accumulation of metallic dendrites on the flow
Porous media approach
Influence of solidification on flow behavior
Flow stop model:
All fluxes across flow stopped cells are zeroed expect energy
For large pressure gradients or body forces (i.e. HPDC)
Volume of Fluid multiphase model:
Inherently provides the spatial distribution between gas and metal phase
Post processing filling and phase distribution allows to assess gas inclusions
Transport equations are solved for the entire fluid domain, thus the gas phase is transported through the domain and interacts with the metal phase
Surface tension effects
Gas entrainment
Counter pressure due to venting and gas compression effects
The production of castings presents complex challenges that can compromise the quality of your products. At CAEXPERTS, we use Simcenter Star-CCM+ to predict and resolve critical defects such as porosity, oxides and runtime errors. Schedule a meeting with us and discover how our advanced solutions can transform your casting processes, ensuring efficiency and superior quality. Contact CAEXPERTS today and raise the standard of your production!