Chris Booth-Morrison

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Chris Booth-Morrison
Research: Evolution of Precipitates in Ni-Based Superalloys
Education: B.Eng Metallurgical Engineering, McGill University
Publications: Publications by Booth-Morrison in our database


Chris Booth-Morrison
Materials Science and Engineering
2220 North Campus Drive
Evanston, IL 60208
Phone: 847.491.5948
Fax: 847.467.2269

The recent surge in fuel costs and the threat of global warming have amplified the urgency for increased fuel efficiency in high-performance engines. The fuel efficiency of an engine is directly related its operating temperature, which is tied to the high-temperature properties of the engine materials. Due to their excellent strength and resistance to both corrosion and creep-induced damage at operating temperatures up to 1373 K, nickel-based superalloys are used for critical components of both aerospace and land-based turbine engines. The high-temperature mechanical properties of these materials are a result of strengthening of the primary γ-matrix phase by the precipitation of a secondary γ'-phase. The decomposition of the γ-matrix via the formation of nanoscale γ'-precipitates is the main subject of my thesis research.

I study the kinetic pathways of the γ-/γ'- phase transformation using high-resolution experimental techniques, namely APT and electron microscopy. Figure 1 below shows the cuboidal γ'-precipitates that form in the γ-matrix of a model Ni-Al-Cr-Ta alloy at 1073 K. In-depth analysis of datasets such as the one shown in the figure below, provide details about the temporal evolution of the γ'-precipitate properties and compositions. These results, in concert with simulations employing advanced computational methods such as first-principles calculations, and Monte-Carlo and thermodynamic simulations, elucidate the kinetic pathways that lead to phase decomposition at high-temperatures. The development of future generations of nickel-based superalloys that can withstand higher operating temperatures will rely on a detailed understanding of the γ/γ'- phase transformation. These complex multi-component alloys will serve as the building blocks for advanced turbine engines that will require less fuel, and produce fewer CO2 greenhouse gas emissions.


Figure 1- Cuboidal γ'-precipitates in a Ni-Al-Cr-Ta alloy heat-treated at 1073 K for 64 h. The γ'-precipitates have aligned along the elastically soft <001> directions. Aluminum and tantalum atoms, shown in red and yellow, respectively, partition preferentially to the γ'-precipitates, while chromium, shown in blue, partitions to the g-matrix. Nickel atoms are omitted for clarity.