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| tutorials:t2 [2019/07/18 15:48] – [T2: Calculating a single equilibrium] pwarczok | tutorials:t2 [2023/07/28 18:11] – [Using the 'Options' window to modify the display] pwarczok |
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| //This tutorial was tested on \\ | //This tutorial was tested on \\ |
| MatCalc version 6.02 rel 1.003 \\ | MatCalc version 6.03 rel 1.000 \\ |
| license: free \\ | license: free \\ |
| database: mc_fe.tdb // | database: mc_fe.tdb // |
| Click {{:tutorials:t2:script:t2_6021003.mcs|here}} to view the script for this tutorial. | Click {{:tutorials:t2:script:t2_6021003.mcs|here}} to view the script for this tutorial. |
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| This tutorial explains how to determine the equilibrium phases at a given temperature, and their phase fractions and compositions. | This tutorial explains how to determine the equilibrium phases at a given temperature, their phase fractions and compositions. |
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| ==== Contents ==== | ==== Contents ==== |
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| ===== Setting up the system ===== | ===== Setting up the system ===== |
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| | The system setup is the very first operation that needs to be performned by MatCalc user. |
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| ==== Opening a thermodynamic database and selecting elements and phases ==== | ==== Opening a thermodynamic database and selecting elements and phases ==== |
| In the **'Global'** menu, select **'Databases'**. | In the **'Global'** menu, select **'Databases'**. |
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| {{:tutorials:t2:img:t2_global_database_6021003.png|Open databases window}} | {{:tutorials:t2:img:t2_global_database_6041000.png|Open databases window}} |
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| A window will appear as shown below. | A window will appear as shown below. |
| In the **'Global'** menu, select **'Composition'**. | In the **'Global'** menu, select **'Composition'**. |
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| {{:tutorials:t2:img:t2_global_composition_6021003.png| Open composition window}} | {{:tutorials:t2:img:t2_global_composition_6041000.png| Open composition window}} |
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| This opens the **'Nominal composition'** box. The lower part of the box gives options for the units in which the composition is to be displayed: mole fraction, weight fraction, u-fraction or weight percent. One of the elements, usually the one with the highest mole fraction, is designated as the **'reference element'**, and the amount of this element is calculated as **1-(sum of the amounts of all other elements)** for compositions expressed in fractional form, or **100-(sum of the amounts of all other elements)** for compositions expressed as percentages. \\ | This opens the **'Nominal composition'** box. The lower part of the box gives options for the units in which the composition is to be displayed: mole fraction, weight fraction, u-fraction or weight percent. One of the elements, usually the one with the highest mole fraction, is designated as the **'reference element'**, and the amount of this element is calculated as **1-(sum of the amounts of all other elements)** for compositions expressed in fractional form, or **100-(sum of the amounts of all other elements)** for compositions expressed as percentages. \\ |
| Iron is set as the reference element by default in the 'mc_fe.tdb' database, as can be seen from the **'Ref. Elem'** column in the composition dialogue box. Another element can be set as the reference by selecting the element name and clicking on the **'Set reference element'** button on the right, or by double-clicking in the **'Ref. Elem'** column by the side of the element name. \\ | Iron is set as the reference element by default in the 'mc_fe.tdb' database, as can be seen from the **'Ref. Elem'** column in the composition dialogue box. Another element can be set as the reference by selecting the element name and clicking on the **'Set reference element'** button on the right, or by double-clicking in the **'Ref. Elem'** column by the side of the element name. \\ |
| To enter a composition of **0.4 wt.% C**, select **'weight percent'** as the unit, then highlight element C. Double-click in the **'Amount'** column or click on the **'Change'** button to modify the composition, then type in **'0.4'** and press **'Enter'**. \\ | To enter a composition of **0.4 wt.% C**, put a checkmark in **'in percent'** box and select **'weight percent'** as the unit, then highlight element **'C'**. Double-click in the **'Amount'** column or click on the **'Change'** button to modify the composition, then type in **'0.4'** and press **'Enter'**. \\ |
| The system is now ready to perform an equilibrium calculation. | The system is now ready to perform an equilibrium calculation. |
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| {{:tutorials:t2:img:t2_system_composition_6021003.png| System composition setup}} | {{:tutorials:t2:img:t2_system_composition_6041000.png| System composition setup}} |
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| Click on **'OK'** to close this window | Click on **'OK'** to close this window |
| From the **'Calc'** menu, select **'Set start values'**. This initializes the calculation variables with reasonable values in order to help the Gibbs free energy minimizer to find a solution which satisfies all the boundary conditions. This command is useful if the solution algorithm seems to be 'stuck' and unable to find an equilibrium. | From the **'Calc'** menu, select **'Set start values'**. This initializes the calculation variables with reasonable values in order to help the Gibbs free energy minimizer to find a solution which satisfies all the boundary conditions. This command is useful if the solution algorithm seems to be 'stuck' and unable to find an equilibrium. |
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| {{:tutorials:t2:img:t2_set_start_values_6021003.png|Set start values}} | {{:tutorials:t2:img:t2_set_start_values_6041000.png|Set start values}} |
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| Once one valid equilibrium has been found, solutions at other temperatures or boundary conditions are much easier to obtain. From the **'Calc'** menu, select **'Equilibrium'**, or click on the {{:tutorials:t2:img:icon_equilibrium.png| MatCalc icon equilibrium}} icon in the toolbar. | Once one valid equilibrium has been found, solutions at other temperatures or boundary conditions are much easier to obtain. From the **'Calc'** menu, select **'Equilibrium'**, or click on the {{:tutorials:t2:img:icon_equilibrium.png| MatCalc icon equilibrium}} icon in the toolbar. |
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| {{:tutorials:t2:img:t2_equilibrium_6021003.png|Equilibrium settings}} | {{:tutorials:t2:img:t2_equilibrium_6041000.png|Equilibrium settings}} |
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| The following window appears: | The following window appears: |
| The **'Options'** window provides display options for the currently highlighted window. In the case of the **'Phase details'** window, the composition can be displayed as a mole fraction, a weight fraction or a u-fraction, and can also be expressed as a percentage if required. | The **'Options'** window provides display options for the currently highlighted window. In the case of the **'Phase details'** window, the composition can be displayed as a mole fraction, a weight fraction or a u-fraction, and can also be expressed as a percentage if required. |
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| {{:tutorials:t2:img:t2_options_window_6001000.png| MatCalc options window}} | {{:tutorials:t2:img:t2_options_window_6041000.png| MatCalc options window}} |
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| ==== Phase status: suspended and fixed phase fraction ==== | ==== Phase status: suspended and fixed phase fraction ==== |
