Difference between revisions of "Chris Booth-Morrison"

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{{Infobox_Biography |
 
{{Infobox_Biography |
 
  title= |
 
  title= |
  given_name=Chris |
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  given_name=Dr. Christopher |
 
  family_name=Booth-Morrison |
 
  family_name=Booth-Morrison |
  image_name=No-photo.png |
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  image_name=Chris2008.jpg|
 
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  research_topic=Evolution of Precipitates in Ni-Based Superalloys|
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  research_topic=Phase Transformations in Ni-based Superalloys|
 
  education=B.Eng Metallurgical Engineering, McGill University|
 
  education=B.Eng Metallurgical Engineering, McGill University|
  phone=|
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  phone=847.491.5883|
 
  fax=847.467.2269|
 
  fax=847.467.2269|
 
  email=c-booth@northwestern.edu|
 
  email=c-booth@northwestern.edu|
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I am a third-year graduate student studying the temporal evolution of nickel-nased superalloys by atom-probe tomography (APT).
 
  
  
'''Ni-Al-Cr'''
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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 to its operating temperature, which is tied to the properties of the engine materials. Nickel-based superalloys are used for critical components of aerospace and land-based turbine engines due to their excellent strength and resistance to both corrosion and creep at temperatures up to 1373 K. The high-temperature mechanical properties of these materials are a result of strengthening of the γ-matrix phase by the precipitation of the γ'-phase. The decomposition of the γ-matrix via the formation of nanoscale γ'-precipitates is the main subject of my thesis research.
  
We are interested in studying the kinetic pathways which lead to the decomposition of the g-matrix phase by the formation of nanometer-sized g'-precipitates. APT of the Ni-Al-Cr nanostructures provides an in-depth look at the compositional and nanostructural evolution of the g’-precipitate phase as it evolves. The decomposition of the g-matrix phase, from the early stages of solute-rich g’-nuclei formation, to the subsequent growth and coarsening of g’-precipitates, can be accessed within the framework of classical nucleation, growth and coarsening theories. The effects of varying the solute concentrations on the temporal evolution of Ni-Al-Cr alloys can be determined in order to provide a more quantitative understanding of the kinetic pathways that lead to phase separation.
 
  
'''Ni-AL-Cr-Ta'''
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I study the kinetic pathways of the &gamma;-/&gamma;'- phase transformation using high-resolution experimental techniques, namely APT and electron microscopy. Figure 1 below shows the cuboidal &gamma;'-precipitates that form in the &gamma;-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 provides details about the temporal evolution of the &gamma;'-precipitate properties and compositions. These results, in concert with first-principles calculations and Monte-Carlo and thermodynamic simulations, elucidate the kinetic pathways that lead to high-temperature phase decomposition. The development of future generations of nickel-based superalloys that can withstand higher operating temperatures will rely on a detailed understanding of the &gamma;/&gamma;'- phase transformation. These complex multi-component alloys will serve as the building blocks for advanced turbine engines that will need less fuel, and produce fewer CO<sub>2</sub> greenhouse gas emissions.
  
The addition of Ta to the ternary Ni-Al-Cr system results in the formation of a large volume fraction of g'-precipitates which demonstrate very strong solute partitioning. Ta has been shown to be a strong g'-precipitate former and solid-solution strenghtener and is known to improve high-temperature strength, creep, fatigue and corrosion properties, all of which are desirable for use in nickel-based superalloys in high-temperature applications.
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<CENTER>[[Image:TA3.jpg]]</CENTER>
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Figure 1- Cuboidal &gamma;'-precipitates in Ni-10.0 Al-8.5 Cr-2.0 Ta at.% aged at 1073 K for 64 h.  The &gamma;'-precipitates have aligned along the elastically soft <001>-type directions. Aluminum and tantalum atoms, shown in red and yellow, respectively, partition preferentially to the &gamma;'-precipitates, while chromium, shown in blue, partitions to the &gamma;-matrix. Nickel atoms are omitted for clarity.

Latest revision as of 17:11, 13 August 2009

Chris Booth-Morrison
Research: Phase Transformations in Ni-based Superalloys
Education: B.Eng Metallurgical Engineering, McGill University
Publications: Publications by Booth-Morrison in our database

Contact

Dr. Christopher Booth-Morrison
Materials Science and Engineering
2220 North Campus Drive
Evanston, IL 60208
Phone: 847.491.5883
Email:
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 to its operating temperature, which is tied to the properties of the engine materials. Nickel-based superalloys are used for critical components of aerospace and land-based turbine engines due to their excellent strength and resistance to both corrosion and creep at temperatures up to 1373 K. The high-temperature mechanical properties of these materials are a result of strengthening of the γ-matrix phase by the precipitation of the 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 provides details about the temporal evolution of the γ'-precipitate properties and compositions. These results, in concert with first-principles calculations and Monte-Carlo and thermodynamic simulations, elucidate the kinetic pathways that lead to high-temperature phase decomposition. 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 need less fuel, and produce fewer CO2 greenhouse gas emissions.


TA3.jpg

Figure 1- Cuboidal γ'-precipitates in Ni-10.0 Al-8.5 Cr-2.0 Ta at.% aged at 1073 K for 64 h. The γ'-precipitates have aligned along the elastically soft <001>-type 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 γ-matrix. Nickel atoms are omitted for clarity.