Data regarding the experimental findings compared with CALPHAD calculations of the AlMo0.5NbTa0.5TiZr refractory high entropy superalloy

This contribution contains the raw data used to compare experimental results with thermodynamic calculations using the CALPHAD method, which is related to the research article “The AlMo0.5NbTa0.5TiZr refractory high entropy superalloy: experimental findings and comparison with calculations using the CALPHAD method” [1], and therefore this article can be used as a basis for interpreting the data contained therein. The AlMo0.5NbTa0.5TiZr refractory superalloy was characterized in the cast and annealed condition (1400 °C for 24 h) in order to measure grain size and to identify and measure the size and area fraction of the phases present. The raw data of this article include X-ray diffraction (XRD) measurements, microstructural characterization by scanning and transmission electron microscopy (SEM and TEM), and elemental analysis by energy dispersive X-ray spectroscopy (EDX). XRD includes the determination of phases and the lattice parameters (A2, B2, and hexagonal structure). Microstructural analysis by scanning and transmission electron microscopy includes (1) identification of composition, size, and volume fraction of the present phases and (2) determination of grain size. Based on these experimental data, it is possible to identify similarities and discrepancies with the data calculated using the CALPHAD method for the alloy under study in Ref. [1], which provides the basis for better and more efficient development of reliable databases.

microscopy includes (1) identification of composition, size, and volume fraction of the present phases and (2) determination of grain size. Based on these experimental data, it is possible to identify similarities and discrepancies with the data calculated using the CALPHAD method for the alloy under study in Ref. [1] , which provides the basis for better and more efficient development of reliable databases.
© 2022 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ ) Table   Subject Material Science Specific subject area Microstructural characterization of a refractory high entropy superalloy Type of data Tables  Images (SEM-BSE Measured raw (XRD patterns, EDX analysis of the phases). Analyzed (lattice parameters, indexation of diffraction patterns in TEM, average grain sizes, thickness of bcc (A2) plates, B2 channels, and area fraction of B2 and Al-Zr-rich phase. Area fraction of the amorphous phase in the Al-Zr-rich phase.

Description of data collection
The XRD patterns were acquired using Seifert XRD 30 0 0 PTS diffractometer operating with a Co-K α radiation source ( λ = 1.7902 Å ).
The SEM images were acquired using an FEI Quanta 3D ESEM integrated with an EDX EDAX Octane Elect SDDs detector: using an acceleration voltage between 20 kV and 30 kV and working distances between 5 and 10 mm. Metallographic samples were prepared by grinding and polishing and used for collecting the SEM-EDX and XRD data. The TEM images and TEM-EDX data were acquired using a JEOL JEM-2200FS TEM and a JED-230 0 0BU EDX detector for the elemental analysis, respectively. The images were taken in conventional dark field (CTEM-DF) and scanning high angle annular dark field (STEM-HAADF) mode. TEM foils were prepared by electropolishing to collect the TEM and TEM-EDX data. Data

Value of the Data
• The data presented in this article includes all the raw data and processing for the AlMo 0.5 NbTa 0.5 TiZr refractory high entropy superalloy in cast and annealed states reported in the related article (Ref. [1] ), which are useful for determining grain size, identification/area fraction of the phase structures and their volume fraction, being important for general alloy characterization. • The procedures used in the determination of grain size, identification of phases, and their volume fraction could be useful for other researchers interested in determining these parameters in any type of alloy. These data may be useful to scientists and researchers in the high entropy alloy community, a field that is constantly evolving. • The compilation of these data (BSE microphotographs, XRD patterns, TEM images and EDX spectra, grain size, and area fraction tables) can be used to develop image analysis algorithms to improve computer-aided analysis of microstructures. • A method for simulating XRD patterns is provided, which can be used in the study of these types of relatively new alloys for which there are few XRD databases. In addition, the composition and structure of each phase in this alloy could be implemented in alloy design software.

Data Description
The XRD data presented in this article are expressed as 2 θ versus intensity plots obtained for the alloy under study (AlMo 0.5 NbTa 0.5 TiZr refractory superalloy, RSA). The raw XRD data are provided as Excel files (see XRD folder in the dataset), and a summary of the recorded diffraction patterns is shown in Fig. 8 of Ref. [1] . The patterns simulated with PowderCell software [2] are included in the dataset (.cel files) for the different phases in the cast (AC) and annealed (AN, 1400 °C for 24 h) specimens. In both cases, most of the diffraction peaks could be indexed according to body-centered cubic, bcc structures (A2, space group Im 3 m and B2, space group P m 3 m ). Besides the bcc-based peaks, additional peaks, corresponding to the Al-Zr-rich hexagonal intermetallic (space group P6 3 /mcm ), were detected. Table 1 summarizes the crystal structure of the phases, their space group, and the lattice parameters obtained by simulating the different phases in both states (AC and AN).
The microstructures of the AC and AN were analyzed by scanning electron microscopy (SEM) equipped with a backscatter electron (BSE) detector. BSE micrographs taken at low and medium magnification are presented to document the grain size "d" in the two different states (see Figs. 1 and 2 of Section 2 ). The average grain size for both states is given in Table 2 . Table 3 summarizes the average area fractions of the Al-Zr and B2 phases in AC and AN. In the AC alloy, the nanostructure consisted of plate-like precipitates with ≈ 2-20 nm thickness embedded in channels with a thickness of ≈ 2-10 nm. The alloy AN exhibited a heterogeneous     Table 3 Average area fraction of the Al-Zr-rich and B2 phases determined with ImageJ software. The uncertainty is given by the standard deviation.

State
Area fraction of the Al-Zr-rich phase (%) Area fraction of the B2 phase (%) As-cast (AC) 8 ± 4 39 ± 4 Annealed (AN, 1400 °C for 24 h) 13 ± 6 37 ± 9 Table 4 Parameters used for the simulation of the present phases in the studied alloy. nanostructure having plate-like precipitates with a thickness of ≈ 10-100 nm embedded in a continuous phase with a thickness of ≈ 3-30 nm. The measurements can be found as Excel files in the dataset (channels.cvs and precipitates.cvs), as well as the images used for the determination.
Since the Al-Zr-rich phase in the AC state is composed of amorphous and crystalline fractions, a method was implemented to determine the crystalline fraction within the analyzed regions (see Section 2 ). The AC sample analyzed by TEM yielded only 5 ± 4% of the Al-Zr-rich regions as crystalline as reported in Ref. [1] . The local chemical compositions of the phases measured at the three different phases in SEM-and TEM-EDX for the studied alloy are given in Table 2 of Ref. [1] and the raw data can be found in the dataset (EDX folder). A table with the name, format, and a brief description of each dataset file contained in Mendeley, is provided at the end of this work.

Experimental Design, Materials and Methods
XRD analysis were conducted for the investigated alloy using a Seifert PTS 30 0 0 diffractometer operating with a Co K α radiation source ( λ K α1 = 1.7902 Å ). The patterns were acquired using a scattering range of 10-100 °for the as-cast state (AC) and 10-120 °for the annealed (AN) state with a step size of 0.05 °and Bragg-Brentano geometry. To obtain the lattice parameters listed in Table 1 , patterns of the identified phases were simulated using the PowderCell software [2] , and the crystal files were manually edited considering the present elements of each phase, the space-group number, the position of the atomic species, and the occupancy of the specific coordinates of the lattice. The lattice parameters were then modified until the exact positions of the peaks in the experimental pattern were reached. Table 4 lists all the parameters chosen to determine the simulated patterns for the lattice parameter identification. Finally, the identification was performed by comparing the experimental and simulated patterns.
Samples for scanning electron microscopy were prepared by conventional metallography with emery paper (SiC) grades p320, p60 0, p120 0, p250 0, and p40 0 0 and polished with a silica solution of 50 nm particle size. Backscattered electron (BSE) images were acquired using a Quanta 3D scanning electron microscope (SEM, FEI Company) with an accelerating voltage of 20-30 kV and a working distance of ≈ 5-10 mm. Grain size ( d ) was determined using the Heyn linear intercept method described in ASTM E112 standard [4] , using four images for each condition.  Tables 5 and 6 summarize the parameters and average Table 5 Parameters and average grain size "d" in the AC state for each drawn line in the four images of Figs. 1 and 2 a of Ref. [1] . The uncertainty is given by the standard deviation of the average grain size of each BSE image.
Transmission electron microscopy images were acquired using a TEM JEOL JEM-2200FS with a field emission gun (FEG), operating at an accelerating voltage of 200 kV. BF and DF CTEM images with their respective selected area diffraction patterns (SADPs) were acquired to identify the phases, in addition to STEM-HAADF and BF images to determine the volume fraction. For the alloy AC, CTEM-DF micrographs and their respective SADPs were taken in the interdendritic zone. Fig. 3 shows a CTEM-BF micrograph of the interdendritic region in AC (a), with the respective SADP along the [001] zone axis (b) used to identify the phases in the interdendritic region. The SADPs used to characterize the bcc-based structures (A2 and B2) were indexed by measuring the lengths of two diffraction vectors and the angle formed by them, and the ratio A/B was compared with the diffraction patterns described in Appendix 4 -Ref. [5] for bcc alloys. The lines labeled "A" and "B" in Fig. 3 b were measured, and the ratio A/ B = 1.414, with a relative angle of 45 °corresponds to bcc oriented along the [001] zone axis, as shown in Fig. 3 b. Table 6 Parameters and average grain size "d " in the AN state for each drawn line in the four images shown in Fig. 2 . The uncertainty is given by the standard deviation of the average grain size of each BSE image.
The area fractions of the Al-Zr-rich phase were determined for both states using BSE images and the B2/A2 phases using STEM-HAADF images with the image analysis software (Im-ageJ) [3] ( Table 3 ). Four BSE images were used to determine the area fraction of the Al-Zr-rich phase in both states. The images were converted to binary images and separated into two different phases using the "threshold" tool of ImageJ. After this step, the binary image was divided into 16 images, which were analyzed separately. Fig. 4 (AC) and Fig. 5 (AN) show the images used to determine the area fraction (left), with the respective binary image separating the Al-Zr-rich phase from the rest of the area (right, black phase on white background). Table 7 (AC)  and Table 8 (AN) show the percentage area of the Al-Zr-rich phase for each analyzed image in Fig. 4 and Fig. 5 , respectively. For the determination of the area fraction of the B2 phase, two images were used for the AC alloy ( Fig. 6 and Fig. 5 d in Ref. [1] ) and three images were used for the AN alloy ( Fig. 7 and Fig. A3a in the supplementary material of Ref. [1] ). Fig. 6 (AC) and Fig. 7 (AN) also show the corresponding binary images in which the B2 phase channels (black) are separated from the rest of the region (white background). Table 9 (AC) and  Table 10 (AN) show the area fraction in% of the B2 phase for each analyzed image in Fig. 6 and Fig. 7 , respectively. The thickness of the B2 channels and A2 plates were measured manually ≈ 200 times using the ImageJ program.

Table 7
Area fraction of the Al-Zr-rich phase in the AC state, determined from the micrographs in Fig. 4 , using ImageJ. The uncertainty is given by the standard deviation. Fig. 4 e Fig. 4 f Fig. 4 g Fig. 4 h Sub-images in the binarized images (shown in Fig. 4 Fig. 8 shows the procedure undertaken to determine the area fraction of the amorphous Al-Zr-rich phase for the original CTEM-DF micrograph in Fig. 6 b of Ref. [1] . The tool "Trainable Weka Segmentation", embedded in the FIJI of ImageJ [3] , allows the separation of three different regions of interest for their area fraction measurement, as shown in Fig. 6 b in Ref. [1] (crystalline (bright regions), amorphous (light gray regions) Al-Zr-rich phase, A2/B2 regions (dark)). In Fig. 8 a, the red color is the amorphous Al-Zr-rich phase (cf. light gray in Fig. 6 b of Ref. [1] ), the blue region is the crystalline region (cf. bright regions in Fig. 6 b of Ref. [1] ), and the lilac region is the surrounding thick A2/B2 in the micrograph (cf. dark regions in Fig. 6 b of Ref. [1] ).

Table 8
Area fraction of the Al-Zr-rich phase in the AN state, determined from the micrographs in Fig. 5 , using ImageJ. The uncertainty is given by the standard deviation. .  Fig. 5 h Sub-images in the binarized images (shown in Fig. 5 [1] . The black phase shown in (b) and (c) represents the B2 phase (channels). The binarized images were divided into 16 images, as shown by the yellow squares and red numbers. Fig. 8 a is then binarized ( Fig. 8 b), where the entire black region is the Al-Zr-rich phase (including the amorphous and crystalline structure, i.e., red plus blue in Fig. 8 a), and the "white region" is the rest of the sample (i.e., thick A2/B2 region in lilac, Fig. 8 a). Fig. 8 b is divided into 16 sub-images to analyze their area fraction separately. Finally, Fig. 8 a is binarized again ( Fig. 8 c), but now considering only the crystalline region (blue phase in Fig. 8 a) and divided into 16 images. Table 11 presents the area fraction of the total Al-Zr-rich phase (second column, from the black phase in Fig. 8 b) and the crystalline phase (third column, from the black phase in Fig. 8 c). Weighing the area fraction of the crystalline phase relative to the total Al-Zr-rich phase, the fourth column in Table 11 gives the amount of crystalline phase embedded in the Al-Zr-rich phase.

Table 9
Area fraction (%) of the B2 phase in the AC state, determined from Fig. 6 b and c, using ImageJ software. The uncertainty is given by the standard deviation. Fig. 6 b Fig. 6 c Sub-images in the binarized images (shown in Fig. 6 b and

Table 10
Area fraction (%) of the B2 phase in the AN state, determined from Fig. 7 c and d, using the program ImageJ. The uncertainty is given by the standard deviation.  The average chemical compositions of the phases listed in Table 2 of Ref. [1] were determined using energy dispersive spectroscopy (EDX) in a Quanta 3D SEM with an EDAX Octane Elect SDDs detector at 30 kV (WD 10 mm) and in a JEOL JEM-2200FS TEM with an EDX Jeol JED-230 0 0BU Si (Li) detector with ultrathin organic/Al window at 200 kV.
The Al-Zr-rich phase composition was determined from the average of the analyzes of two regions with TEM-EDX measurements for each state (AC and AN). The dendritic and interdendritic compositions were determined from the average of five spot analyzes (SEM-EDX) for the AC in the electron-transparent regions (thickness < 1 μm) of a TEM specimen.
The chemical compositions of the A2 and B2 phases were determined from the average of three spot analyzes (TEM-EDX) for the AN specimen, and finally, the chemical composition of the bright phase surrounding the Al-Zr-rich phase was determined using the average of three spot analyzes (SEM-EDX) in the AN alloy.

Table 11
Area fraction of the Al-Zr-rich phase and crystalline phase in the Al-Zr-rich phase determined from the images in Fig. 8 a-c. Sub-images from Fig. 8

b,c
Area fraction only Al-Zr-phase ( Fig. 8 b) Area fraction only crystalline phase ( Fig. 8   Analyzed CTEM-DF_AC_Al-Zr_crystals.csv Excel file that contains the% of area fraction of the crystalline area (Al-Zr-rich phase) in the cast state (Fig. 8c) Analyzed STEM-HAADF_AC_bcc-B2areafraction.dm3 STEM-HAADF micrograph N °1 of the AC alloy used to determine the area fraction of A2/B2 phases (Fig. 6a