The Stress and Strain of Designing New Materials with Professor Boakye-Yiadom

Creating the next generation of advanced materials is no easy task, but Lassonde School of Engineering Professor Solomon Boakye-Yiadom is aiming for just that.

An assistant professor in the Mechanical Engineering Department, Professor Boakye-Yiadom has two central pillars to his research: the design of novel materials including biomaterials and the characterization of existing materials.

One arm of Professor Boakye-Yiadom’s research is investigating the deformation behaviour of materials used in vehicles when impacted. This collaborative research project is a 5 year, $3.195-million NSERC Alliance funded in collaboration with the University of Alberta, the University of British Columbia, General Dynamics, NP Aerospace Ltd, and the Defence Research and Development Canada. Professor Boakye-Yiadom is the academic lead of the metallic characterization portfolio of this project which is being led by Dr. James Hogan from the University of Alberta. This work will develop new Canadian-made ceramic-based solutions for vehicles. As part of the analysis, Professor Boakye-Yiadom is investigating how the materials on the vehicles deform when deformed under varying loading conditions. To do this, Professor Boakye-Yiadom utilizes an extreme mechanical loading setup, which allows for dynamic stress and strain (deformation) measurements of materials.

The other arm of Professor Boakye-Yiadom’s work is centred around the development of novel materials. Recently funded through the Canada Foundation for Innovation: John Evans Leadership Fund (CFI JELF) program, Professor Boakye-Yiadom is setting up a facility that will enable the creation of new high entropy alloys (HEA). Recently HEA has been shown to possess exceptional properties exceeding those of conventional alloys. These can include greater fracture toughness, high/low-temperature strength, or high resistance to extreme chemical environments. These HEA have equal concentrations of elements, as opposed to traditional alloys which have unequal elemental distributions. This gives the materials unique structures with applications across a wide variety of industries.

“Most metallic alloys are predominantly composed of one predominant element,” said Boakye-Yiadom. “Steel, for example, is mostly iron with only small bits of carbon and other alloying elements present. For a high entropy alloy – just look at the periodic table, there are so many possible combinations of five or more elements with equal concentrations.”

Through the CFI JELF program, Professor Boakye-Yiadom will enhance 3D printing at Lassonde and bring the first metal 3D printer to the university. With it, he and his team will be creating these “cocktails” of elements by mixing metal powders at specific ratios which will facilitate the production of high entropy alloy blocks from the 3D printer. This work is highly experimental, one of his PhD students is currently developing software that can pick elements on the periodic table and identify potential combinations. In essence, the sky is the limit, and professor Boakye-Yiadom and his team are investigating all potential combinations of elements that could yield a high entropy alloy.

“We want to create new materials that will push the boundaries of engineering applications,” said Boakye-Yiadom. “Existing materials in the aerospace or automotive industry go through the rigorous certification process but they have limitations in performance – we need to look elsewhere if we want to find advanced materials for new applications.”