Iranian Journal of Materials Science and Engineering

HIGHLIGHTS:
 Gd-doping enhances IT-SOFC cathode performance via TPB density.
 Mixed BaSrCoO3−δ phases reduce area-specific resistance.
 Sol–gel thermolysis enables controlled synthesis of Ba0.5Sr0.5−xGdxCoO3−δ.
 Oxygen-vacancy engineering improves ORR kinetics in BaSr1−xGdxCo2O5+δ.
 Ba0.5Sr0.3Gd0.2CoO3−δ shows optimized electrochemical performance.

• A full factorial design was employed to quantify the effects of baseplate thickness, laser power, dwell time, and interruption strategy (layers per interruption) on residual stress and distortion in DED.
• A 3D thermo–mechanical model was developed and experimentally validated using X-ray diffraction (XRD) residual stress measurements.
• Optimized processing conditions reduced residual stress by 43% and dimensional distortion by 33% relative to the baseline setup.
• Baseplate thickness was identified as the most influential factor on both residual stress and distortion, while dwell time showed the least effect.
• The study reports, for the first time, the combined impact of baseplate thickness, dwell time, interruption layer count, and laser power on residual stress and distortion in DED, providing a quantitative basis for process optimization.

 

- Aging always seems to promote hydrotalcite crystallite growth.
- The first two hours of aging promotes zinc incorporation into malachite structure.
- The second two hours of aging seems to partially deplete the malachite phase of Zn.
- Excessive aging deteriorates the post‑calcination BET surface area of the system.
- Higher Cu⁰ surface area values are yielded at moderate aging durations.
 

1. The production of Mo-30wt% W alloy by simultaneous reduction of molybdenum and tungsten oxides
2. Investigation on the effect of reduction temperature on formation of this alloy at temperatures between 600-1050℃
3. Complete reduction of WO3 and MoO3, by H2 in the temperature between 1000-1100 °C
4. Study on the mechanism of mass transform between Mo and W
 

Highlights

• Rapid thermodynamic modeling predicts secondary phase fractions.
• Experiments validated the thermodynamic screening framework.
• Predicted phase fractions strongly correlate with corrosion.
• ZX31 (Mg-2.6Zn-1Ca) exhibits optimal biocorrosion resistance.
• Optimized secondary phases led to a low rate of (216 µA/cm²).

1. A new synthesis route for (1-x) PFN-PT/x(Ca,Sr)ZrO₃ ceramic composites was developed.
Pure CaZrO₃ (CZ) and SrZrO₃ (SZ) powders were synthesized via sol-gel auto-combustion,
and PFN-PT ceramic was prepared by the solid-state method. Subsequently, composite
powders were prepared by ball milling the CZ(SZ) and PFN-PT powders in ethanol for 24
hours.
2. A novel co-doping strategy using (Ca,Sr)ZrO₃ significantly enhances the dielectric and
ferroelectric properties of PFN–PT ceramics by precisely engineering the critical
Morphotropic Phase Boundary (MPB). This approach yields superior polarization
performance, paving the way for advanced multifunctional electroceramic devices.
3. The co-doping effectively tunes the phase structure, leading to significantly enhanced
dielectric and ferroelectric properties. Optimal doping (x=0.04) results in a maximum
remanent polarization (Pr) of 34.26 μC/cm², showcasing potential for advanced
multifunctional electronic materials.

Highlights

• Twin boundaries exhibit a dual role in strengthening and weakening Ni-based superalloys.

• Increasing twin boundary density reduces yield strength due to stress concentration effects.

• Plastic deformation is dominated by dislocation slip in γ and γ′ phases on {111} planes.

• Crack initiation and propagation preferentially occur along twin boundaries and interfaces.


 

Highlights

1. The influence of the anodizing time on the anodized layer thickness was investigated.
2. The possibility of the laser welding of anodized T6-6061 aluminum alloy containing the maximum anodized layer thickness was successfully examined.
3. The results inferred the homogenous distribution of the elements within the weldment. In the meantime, the growth of dendrites across the weldment shows the concentration of elements in the interdendritic regions of the weldment.

Highlights

1. The influence of the anodizing time on the anodized layer thickness was investigated.
2. The possibility of the laser welding of anodized T6-6061 aluminum alloy containing the maximum anodized layer thickness was successfully examined.
3. The results inferred the homogenous distribution of the elements within the weldment. In the meantime, the growth of dendrites across the weldment shows the concentration of elements in the interdendritic regions of the weldment.

 

  Highlights

• A Taguchi L-8 orthogonal array design was systematically employed to optimize the combined influence of solutionizing and artificial aging on Al-12Si-Cu alloy properties.
• Microstructural refinement, particularly eutectic silicon spheroidization, was identified as the key factor that physically disrupts cathodic paths, effectively mitigating corrosion propagation.
• A clear trade-off was established: Maximum microhardness 155 HV was achieved at S3 500C (3h)  + 180 C (5 h), while the best corrosion resistance 4.76 mpy required the shorter treatment time of  S1.
• ANOVA identified the aging temperature as the most influential factor (contributing over 84 % to microhardness) governing the final balance of mechanical and corrosion properties.

Highlights

• CoFe₂O₄ nanoparticles were synthesized by the sol–gel method and sintered at 400–1000°C.
• XRD confirmed a stable cubic spinel structure, with crystallite size increasing with sintering temperature.
• The sample sintered at 800°C exhibited the most uniform morphology and the lowest dielectric loss at 1 kHz.
• Saturation magnetization increased to 68 emu/g at 1000°C, while coercivity peaked at 715 Oe at 800°C.
• Sintering at 800°C provided the best overall balance of structural, dielectric, and magnetic properties.

Highlights

• Ni–Co–CeO₂ nano-composite coatings were successfully fabricated via a sol-enhanced electrodeposition method using HMTA as a precipitating agent.
• Increasing current density from 10 to 30 mA.cm^-2 decreased CeO₂ incorporation from 12.2 wt% to 7.1 wt% while slightly increasing Ni and Co contents.
• CeO₂ nanoparticles induced grain refinement, transformed the acicular Ni–Co morphology into a fine-grained heterogeneous structure, and promoted the formation of FCC Ni phases within the HCP Co matrix.
• The coating deposited at 20 mA.cm^-2 exhibited optimal electrochemical performance, delivering a discharge time of 92 seconds (a 77% improvement over the particle-free Ni–Co alloy).
• CeO₂ acted as an active co-catalyst via Ce³⁺/Ce⁴⁺ redox couples, resolving oxidation peaks (0.265 V and 0.321 V) and reducing peak potential separation (ΔE_p) to 0.148 V.
• Increasing current density systematically reduced bulk resistance (R_p) from 11,024 to 2,216 Ω.cm^-2 by minimizing the semiconducting CeO₂ phase while enhancing surface porosity and active surface area.
• An optimal balance between metallic conductivity (Ni–Co matrix) and catalytic activity (CeO₂ nanoparticles) was achieved at 20 mA.cm^-2, maximizing charge storage and transfer kinetics.