Alloy Strength - Ti Property Model Settings
The Alloy Strength - Ti Property Model, available with the Property Model Calculator and the Titanium Model Library, calculates the strength and hardness for Ti-base alloys.
About the Alloy Strength - Ti Property Model
For an example see PM_Ti_02: Alloy Strength for Ti-O
To run calculations with the Titanium Models requires a valid maintenance license plus a license for the TCTI (version 6 and newer) database. For some Property Models, additional recommendations for the database version to use is indicated in its description. Also see our website to learn more about the Titanium Model Library.
About the Contributions
The model can be configured to include contributions from:
- Intrinsic strength / hardness: The base line strength expressed as the weighted average of the strength for the pure elements in the system. If any of grade 1-4 is chosen as the base, a solid solution strengthening contribution stemming from impurities of Fe, C, N, H, and O is added to the weighted average of pure element strength.
- Solid solution strengthening / hardening: The contribution to strength from solid solution calculated as the sum of contributions from binary interactions.
- Grain boundary strengthening / hardening: The contribution to strength from grain boundaries described by the Hall-Petch relationshipis described by the Hall-Petch relation.
- Precipitation strengthening / hardening: The contribution to strength from precipitation, described by the model developed by Deschamps.
- Constant strength / hardness: This contribution is a constant addition to the overall strength. It is a true constant in the sense that it is not converted between either strength or hardness, nor between Mpa or Vickers units.
For more details about these contributions, see About the Alloy Strength - Ti Property Model.
Configuration Settings
The settings are found on the Property Model Calculator when Alloy Strength - Ti is selected under Titanium Models.
When working in the Configuration window, click the Description tab for more information about the Model.
For the details about the Condition Definitions, Calculation Type, Timeout in minutes, Parallel Calculation, and other calculation associated settings, see Property Model Calculator: Configuration Window Settings.
Titanium Base Grade
Select a Titanium base grade from the list. Impurities have a strong solid solution hardening effect. When you select a Ti-grade as the base for the alloys system, this effect is taken into account. The default, Iodide Titanium, is pure Ti with no impurity elements, i.e. this excludes this contribution to the intrinsic hardness. Otherwise choose a Ti-base grade from the list, where the compositions for the available grades are also listed:
- Grade 1 35A: Ti-0.2Fe-0.18O-0.08C-0.03N-0.015H (wt%)
- Grade 2 50A: Ti-0.3Fe-0.25O-0.08C-0.03N-0.015H (wt%)
- Grade 3 65A: Ti-0.3Fe-0.35O-0.08C-0.05N-0.015H (wt%)
- Grade 4 75A: Ti-0.5Fe-0.4O-0.08C-0.05N-0.015H (wt%)
Evaluation Temperature
Enter an Evaluation temperature, which is the temperature at which the hardness is evaluated.
Grain Boundary Strengthening
Click to select the Grain boundary strengthening checkbox to include calculated grain boundary strengthening (
).
Grain Size
This setting is available when the Grain boundary strengthening checkbox is selected.
Enter the Grain size [μm], which is the grain diameter in micrometers (μm). The default is 100 μm.
User-defined Hall-Petch Coefficient
This setting is available when the Grain boundary strengthening checkbox is selected. By default, a suitable default Hall-Petch coefficient is automatically calculated by the model.
Alternatively, select the User defined Hall-Petch coefficient checkbox and enter a different Hall-Petch coefficient: 
in MPa μm1/2.
Precipitation Strengthening
Click to select the Precipitation strengthening checkbox to include calculated precipitation strengthening (
). Then continue to define the settings under Additional Precipitation Strengthening Settings.
Constant Strength Addition
Enter a Constant strength addition. This strength contribution can be used to displace the calculated result in the y-direction. Function input is allowed, e.g., 1000*w(Al).
Additional Precipitation Strengthening Settings
The following settings are available when the Precipitation strengthening checkbox is selected.
Precipitate Phase
Select a Precipitate phase from the list. One phase can be chosen to contribute to the alloy strength.
The various forms of alpha martensite HCP (
, 
, or 
) are not explicitly distinguished and are collectively described by the phase HCP_A3 in terms of thermodynamic properties.
Precipitate Radius
Enter a Precipitate radius, which is the mean radius of the precipitates. The default is 1.0E-8.
Critical Radius
Enter a Critical radius. This is the mean precipitate radius where the mechanism that dislocations pass precipitates changes from shearing (
) to looping (
). The default is 1.0E-8.
Taylor Factor
Enter a value for the Taylor factor. The default is 3.0.
The value of the Taylor factor accounts for texture in the material. Normally the value is between 2.24 and 3.06 for random orientations.
Shear Modulus
Enter the word Calculated (not case sensitive) in this field to calculate the shear modulus of the matrix phase from the parameters in the thermodynamic TCS Ti/TiAl-based Alloys Database (TCTI) (version TCTI6 and higher), which contains the elastic properties.
Additionally, values or functions, expressed in Pa, are also accepted as input. If the shear modulus cannot be calculated or evaluated from the input, a default value of 4.5E10 Pa is used, which is close to the value for pure Ti at room temperature.
Burgers Vector
Enter a value for the Burgers vector, which is the burgers vector of the matrix phase. The unit is meter (m) and the default is 2.5E-10.
Plot Renderer Settings
Plot Renderer and Plot Renderer: Configuration Settings
When setting up your calculation on the Plot Renderer and/or Table Renderer, the following axis variables are available for the conditions defined on the Property Model Calculator.
The various hardness or hardening quantities are treated separately from the various strength or strengthening quantities and each (hardness and strength) are plotted on the respective axes. When setting up the simulation, the Configuration window (when in Grouped Mode) shows either Vickers Hardness or Strength. This corresponds to the labeling of axes in the Visualizations window when plotting two or more quantities of the same type. The legend then lists the specific quantity names selected on the Configuration window.
Plot Quantities
- Temperature
- Total Hardness
- Total Yield Strength
- Intrinsic Hardness
- Total Solid Solution Hardening
- Solid Solution Hardening for Beta Phase
- Solid Solution Hardening for Alpha Phase
- Constant strength addition [MPa]
- Amount of Phases