The material configuration file contains information on mechanical properties, constant thermal properties, and other parameters used in Additive Science. This file is read as part of the input when running any simulation, but not every setting is used in every simulation.
Settings in the material configuration file are defined in the following table.
| Setting | Definition | Units | Value |
| name | Name for the material. Must be unique. | - | |
| description | Additional comments (optional) | - | |
| coreVersion | Version of the current material configuration file. This can be changed when updating new versions of the same material. | - | |
| solidThermalConductivityAtRoomTemperature | Thermal conductivity of bulk material at room temperature (298 K) | W/m/K | |
| solidDensityAtRoomTemperature | Density of bulk material at room temperature (298 K) | kg/m^3 | |
| solidSpecificHeatAtRoomTemperature | Specific heat of bulk material at room temperature (298 K) | J/kg/K | |
| purgingGasConvectionCoefficient | Convection coefficient between the solid and gas during processing | W/(m^2*K) | 12.5 |
| solidusTemperature | Maximum temperature at which the material is completely solid | K | |
| liquidusTemperature | Minimum temperature at which the material is completely liquid | K | |
| vaporizationTemperature | Temperature at which material has completely changed from liquid to vapor | K | |
| thermalExpansionCoefficient | Coefficient of thermal expansion. | 1/K | |
| elasticModulus | Elastic modulus of build material. | Pa | |
| elasticModulusOfBase | Elastic modulus of base material. | Pa | |
| poissonRatio | Poisson ratio | - | |
| materialYieldStrength | Yield strength | Pa | |
| supportYieldStrengthRatio | Factor to reduce the yield strength and elastic modulus of support material | - | |
| anisotropicStrainCoefficientParallel | Multiplier on the predicted strain in the direction that the laser is scanning for the major fill rasters | - | 1.5 |
| anisotropicStrainCoefficientPerpendicular | Multiplier on the predicted strain orthogonal to the direction that the laser is scanning for the major fill rasters and in the plane of the surface of the build plate | - | 0.5 |
| anisotropicStrainCoefficientZ | Multiplier on the predicted strain in the Z direction | - | 1 |
| hardeningFactor | Factor relating the elastic modulus to the tangent modulus for plasticity simulations (Tangent Modulus = elasticModulus*hardeningFactor ) | - | |
| nucleationConstantInterface | Controls the heterogeneous nucleation rate (on existing solid interfaces) during solidification for the microstructure solver | 1/m/K^2 | 1000 |
| nucleationConstantBulk | Controls the homogenous nucleation rate (in bulk of the microstructure simulation domain) during solidification for the microstructure solver | 1/m^2/K^2 | 1000 |
| penetrationDepthPowderCoeffA | Coefficients used in thermal analyses to control absorptivity and penetration depth. These settings are determined through tuning. | - | |
| penetrationDepthPowderCoeffB | |||
| penetrationDepthSolidCoeffA | |||
| penetrationDepthSolidCoeffB | |||
| absorptivityPowderCoeffA | |||
| absorptivityPowderCoeffB | |||
| absorptivitySolidCoeffA | |||
| absorptivitySolidCoeffB | |||
| absorptivityMinimum | Minimum fraction of energy absorbed by the melt pool (for example, 0.2 means 20%) | Dimensionless fraction | 0.2 [a] |
| absorptivityMaximum | Maximum fraction of energy absorbed by the melt pool (for example, 0.8 means 80%) | Dimensionless fraction | 0.8 [a] |
| penetrationDepthMinimum | Lower limit for penetration depth | m | 2.7E-5 [a] |
| penetrationDepthMaximum | Upper limit for penetration depth | m | 4.1E-4 [a] |
| powderPackingDensity | Density of powder material relative to the solid | Dimensionless fraction | 0.6 [a] |
| available | True | ||
| key | Unique name for the material. Must be 16 characters or fewer, contain no spaces, and can be the same as the "name." | - | |
| thermalSimulationApproved | True or false flag signifying whether the material can be used for thermal simulations. | - | True |
| microstructureSimulationApproved | True or false flag signifying whether the material can be used for microstructure simulations. | - | False |
[a] Recommended value
These inputs are laid out in a .json file format with material properties held within the configuration parameter. An example of this file is provided as MaterialConfigurationExample.json. When editing values from the example or creating your own material configuration file, be sure to follow the json format to avoid errors.