Thermodynamic parameters were assessed for the MgO–FeOx system and combined with already available descriptions of ZrO2-FeOx and ZrO2-MgO systems to calculate preliminary phase diagrams for planning experimental investigations. Samples of selected compositions were heat treated at 1523, 1673 and 1873 K and characterized using x-ray and scanning electron microscopy combined with energy dispersive x-ray spectroscopy (SEM/EDX). Experiments indicated extension of cubic ZrO2 solid solution into the ternary system at 1873 K (75 mol.% ZrO2, 10 mol.% FeOx and 15 mol.% MgO) and limited solubility of 4 mol.% ZrO2 in spinel phase. Based on the obtained results thermodynamic parameters of C-ZrO2 and spinel phase were optimized.

In this study, DAMASK was used to model and elucidate the microstructural deformation behavior of sintered X3CrMnNi16-7-6 TRIP steel. The recently developed TRIP-TWIP material model was used within the DAMASK framework. Material optimization was performed using the least computationally expensive method, which yielded the desired results. The physical parameters of the material model were identified and tuned to fit the experimental observations. This tuned material model was used to run simulations utilizing 2D EBSD data. The local deformation, transformation, and twinning behaviors of the material under quasi-static tensile and compressive loads were analyzed. The results of this are in good agreement with previous experimental observations. The phenomena of dislocation glide, twinning, martensitic transformation, stress evolution, and dislocation pinning in different deformation stages are discussed.

Phase relations in the MgO–TiO2 and Al2O3–MgO–TiO2 systems have been studied experimentally using X‐ray diffraction, scanning electron microscopy combined with dispersive X‐ray spectrometry, and differential thermal analysis. The heat capacity measurements of the Mg2TiO4, MgTiO3, and MgTi2O5 compounds have been carried out in the temperature range of 473‐1373 K using DSC. A new thermodynamic description of the MgO–TiO2 system has been derived based on obtained experimental results, data from literature, and taking into account the cation disordering of the intermediate compounds Mg2TiO4 and MgTi2O5. The liquid phase was described by the two‐sublattice partially ionic model (Mg+2,Ti+2,Ti+3)(O−2,Va,O,TiO2). For the Al2O3–MgO–TiO2 system: the solid‐state invariant reaction involving the intermediate phase of pseudobrookite solid solution have been found at the temperature of 1433 K. On the liquidus surface, the eutectic invariant reaction has been established at 1843 K and the transitional one—at 2006 K. Based on the obtained experimental results isothermal sections within the range 1269‐1697 K of the ternary system have been predicted. The MgTi2O5–Al2TiO5 section has been constructed.

The phase relations in the ZrO2–La2O3–Gd2O3 ternary system were experimentally studied and thermodynamic modeling was performed. Selected compositions were synthesized using the co‐precipitation method, equilibrated at 1673 and 1873 K, and analyzed using X‐ray diffraction (XRD) and scanning electron microscopy (SEM/EDX). The phase transformations were investigated using differential thermal analysis (DTA), and the heat capacities of (La1 − xGdx)2Zr2O7 (x = 0.25, 0.50, 0.75) compounds were measured using differential scanning calorimetry (DSC). Experimental studies showed a substantial extension of the fluorite phase into the ternary system and solid‐state transformations involving phases A (hexagonal), fluorite, B (monoclinic), and pyrochlore at 1845 K (DTA). Additionally, thermodynamic modeling was performed using the CALPHAD (CALculation of PHAse Diagrams) approach. Comparing the new experimental data and the calculations based on ternary extrapolations of the binary systems revealed major inconsistencies. One source of inconsistencies was related to the calculated phase equilibria in the binary La2O3–Gd2O3 system. Additional experimental investigation of the binary system indicated an underestimated solubility of La2O3 in the B phase in the temperature range 1673‐1873 K. Based on these new data, the mixing parameters of the B phase were re‐assessed. The new experimental results for the ternary system were used to optimize the mixing parameters of the fluorite, B and C (cubic) phases. All new experimental data were well reproduced by the improved thermodynamic description of the ternary system.

Phase relations in the ZrO 2 -TiO 2 system were studied experimentally using X-ray diffraction (XRD), scanning electron microscopy combined with dispersive X-ray spectrometry (SEM/EDX) and differential thermal analysis (DTA). The homogeneity ranges of ZrO 2 and TiO 2 , as well as high temperature disordered b-(Zr x Ti 1Àx ) 2 O 4 compound were defined in the temperature range of 1700-2040 K. Temperature and composition of eutectic reaction were measured. The standard enthalpy of formation of the b-ZrTiO 4 compound was obtained using high-temperature oxide-melt solution calorimetry. High temperature heat capacity measurement for the b-ZrTiO 4 compound was performed in the temperature range from 250 K to 1200 K. Thermodynamic description of ZrO 2 -TiO 2 system has been derived based on obtained experimental results and data from literature. K E Y W O R D SGibbs energy of formation, modeling/model, phase equilibria, thermal analysis, thermodynamics 1 | INTRODUCTION ZrO 2 -based ceramic materials are widely applied in industry. The b-ZrTiO 4 is well-known compound in the field of electro-ceramics where it is used in the dielectric resonators and devices for telecommunications.1 b-ZrTiO 4 shows anisotropic thermal expansion and therefore has potential as thermal shock resistance application. In the work of L opez-L opez et al 1 the thermomechanical properties of this compound were investigated and it was proposed for application as a constituent of thermal shock resistance materials. It should be mentioned, materials based on the ZrO 2 -TiO 2 system are of interest due to their applications in electrical and optical devices such as capacitors, piezoelectric sensors, ultrasonic motors, and microwave dielectric resonators. [2][3][4][5][6][7] It is also useful as high-temperature pigments and bi-functional catalyst. 8,9The materials based on Al 2 TiO 5 -ZrTiO 4 -ZrO 2 system are new promising kinds of ceramic composite material with low thermal expansion coefficient and high-temperature stability. 10 The system ZrO 2 -TiO 2 is part of the ZrO 2 -Y 2 O 3 -TiO 2 system which presents interest for thermal barrier coating applications. It was shown that co-doping of ZrO 2 with Y 2 O 3 and TiO 2 resulted in strong stabilization of tetragonal modification of YSZ (Yttria Stibilized Zirconia) which is used as TBC (Thermal Barrier Coating). 11The phase relations in the ZrO 2 -TiO 2 system are important for application in metal matrix composite. High alloyed ductile TRIP-steel (Transformation Induced Plasticity) exhibited extraordinary high values of specific energy absorption due to reinforcing by Mg-PSZ-ceramic (MgO Partially Stabilized Zirconia).12 Since, the Mg-PSZ-ceramic shows a martensitic transformation of tetragonal to monoclinic phase during deformation resulting in additional strength increase in the TRIP-steel. 13 In the work of Weigelt et al, 14 it was shown, that a minor addition of titanium improves the densification of the matrix material and the bonding between the zirconia particles and the TRIP steel ma...