Computational & Experimental Materials Engineering Laboratory

Prof. El-Awady joins a team of international scientists who published a new review paper in Nature Materials that highlights recent developments in bioinspired nanocomposites, and how engineers are using nature to design tougher, more sustainable materials. Check it out!

Hierarchically structured bioinspired nanocomposites - Nature Materials This Review discusses recent progress in bioinspired nanocomposite design, emphasizing the role of hierarchical structuring at distinct length scales to create multifunctional, lightweight and robust structural materials for diverse technological applications.

Nothing beats an in-person conference where you meet old friends and make new friends. Where you are able to discuss new ideas and build on going collaborations! It was great being back at the TMS annual meeting and looking forward to more successful in-person meetings in the near future!

Our postdoctoral fellow Dr. Markus Sudmanns and Prof. El-Awady publish a new study in Acta Materialia on modeling dislocation plasticity in High Entropy Alloys. The study focuses on the effects of short range ordering on the evolution of plasticity in these new alloys. Check it out!

In a collaboration with Prof. Somnath Ghosh's group at JHU we have published a new micro-mechanical investigation of the thermo-mechanical properties of micro-architectured tungsten coatings using both in situ micro-compression experiments inside a scanning electron microscope (SEM) as well as image-based crystal plasticity finite element method (CPFEM) simulations. These coatings have micro-patterned surfaces with a low-porosity microstructure, which gives them unique themral and sputtering resistance properties (e.g. distribute the heat flux more effectively, enhanced thermal fatigue resistance due to the relatively-free expansion and contraction of the coating during thermal cyclic loading, and overall sputtering rate due to ion bombardment of these coatings).

In our current study we show that these coatings exhibit a brittle-to-ductile transition in deformation mode. At temperatures below 573 K, catastrophic failure at high strength but low strains, which is characterized by intergranular fracture and buckling of individual columnar grains was observed and attributed to the high lattice friction and the intrinsic void/pores present along the grain boundaries. At higher temperatures, the lower lattice friction gives rise to enhanced plasticity at the tip of the pre-existing grain boundary defects and the material exhibits a continuous plastic flow with more homogeneous deformation. While the strength of the coating inevitably decreases with increasing temperature, the enhanced plastic deformation offers great defect tolerance capability that suppresses the structural instability observed at low temperatures.

Finally, the experimental and simulation observations suggest that the structural integrity of these coatings can be improved through either reducing the grain aspect ratio and/or improving the GB toughness. These generally can be tailored through changing the processing parameters during the chemical v***r deposition of these coatings.

Check out the paper!

Micro-mechanical investigation of the thermo-mechanical properties of micro-architectured tungsten coatings The thermo-mechanical response of micro-architectured tungsten coatings is characterized in the temperature range of 293 to 673 K using both in situ m…