Canada is a global leader in the production and manufacture of metallic alloys and their composites. These are critical for the transportation, resource and energy sectors representing 17% of Canada’s GDP (2010) and 5% of Alberta’s GDP (2012). To reduce greenhouse gas emissions while improving the standard of living and the sustainable lifestyle of Canadians, advanced bulk materials (ABM) must be developed, and innovative and cost effective processes and products must be designed, often using recycled materials.
ABMs involve the controlled addition of C, Mn and Nb in steels or Cu, Si, Sc, Ce and/or Mg in aluminum with advanced processing approaches. These small but important additions of elements are primarily responsible for improving the mechanical, corrosion or other properties. In addition, impurities in alloys must be controlled (e.g. Cu, S and O in steel and Fe in aluminum). Prof Henein’s award winning research on the processing of ABMs is carried out by developing and using state of the art research tools (e.g., in plant measurements, TEM, microtomography, neutron scattering, EBSD and mathematical modelling).
Examples of ABMs research in Henein’s group are in rapid solidification of aluminum alloys and tool steels for automotive and aerospace applications, and processing of steels for oil and gas transmission pipelines and tubular products. The following provides brief details of his major contributions.
The Bridgeman method was developed to study and generate fundamental knowledge on the solidification of slow cooled alloys. For the regime of rapid solidification (RS), high undercoolings and high cooling rates, the electromagnetic levitation (EML) and Impulse Atomization (IA) are used. We have developed IA by which the quantitative characterization of powder microstructures generated in a type of drop tube provides comprehensive and quantitative solidification knowledge under RS conditions. This knowledge provides a clear description of the solidification path of these RS alloys and forms the basis of the Integrated Computation Engineering (ICME) of RS structures. Its use enhances alloy properties by reducing the negative effects of iron impurities to increase the recyclability of aluminum alloys and increasing the supersaturation of alloying elements (e.g. Cu, Si, Zr, Sc) in casting operations such as strip casting, additive manufacturing (3D printing), die casting, welding, metal powder production and spray forming. This research has been recognized with a Best Paper Award from CMQ (2011) and several Invited and Plenary presentations at the Conference of Metallurgists (2014, 2015), EPFL, Lausanne (2014), UCranfield, UK (2016) and CIM Distinguished Lecturer (2016-17). Several experiments in this area will be carried out on the International Space Station (ISS) starting in 2017. IA is being commercialized with a $5M investment for the generation of metallic powders for 3D printing.
Other award winning research has been our collaboration with industry to develop new grades of pipeline and tubular steels for the transmission of natural gas, alternative energy sources and CO2 for sequestering and downhole applications. We have shown that the matrix is responsible for 55 to 60% of the steel YS or UTS, while micro-additions of alloying elements in the form of solid solution or precipitates account for the remaining 40%. Our research played a major role in EVRAZ Inc. NA producing the first X100 linepipe in North America and has been recognized with the Charles Hatchett Award by IOM3 and a Plenary talk at Energy and Materials Conference 2014 co-sponsored by the Chinese Society of Metals and TMS and an Invited talk at the Pan American Congress, TMS 2017.
Surface and transport conditions play a pivotal role in many metals processing operations and are strongly affected by minute additions of alloying elements. The need for reliable property data of melts as a function of temperature and atmosphere is critical for many processing operations such as refining, welding and casting of alloys. We have developed a novel and unique method, discharge crucible (DC), to simultaneously measure the surface tension, viscosity and density of fluids. All other methods only generate data for two of these properties. The DC yields accurate data at a fraction of the time of other classical methods (e.g. sessile drop, modified capillary, etc.). We have applied the DC to Sn, Sb, Zn, Sn-Sb, Sn-Ag alloys, Al, and AZ91D. The results were correlated with the thermodynamic properties of these alloys and for AZ91D the effect of an inerting cover gas on the properties of the molten alloy was demonstrated. We have been invited to join the Thermolab research group in Europe to measure these properties for comparison on the ISS. This research was recognized with a Best Paper Award and a Plenary presentation at the International Conference for Thermophysiscs and an invited paper in the International Journal of Thermophysics .
Keywords: Materials process engineering, additive manufacturing, rapid solidification, steel processing, pipeline steels, thermophysical property measurements, microgravity materials science