Research and Teaching Interests
Physical phenomena in non-ferrous casting: hot tearing, continuous casting, EB melting and refining, vaccuum casting, finite element-based heat flow and stress codes, optimization of industrial casting processes, mathematical modeling
Current Research Work
Thus far, my work has adopted an approach that combines both industrial and laboratory experiments with mathematical modeling. General finite element-based heat flow and stress codes have been developed in-house and applied, together with commercial codes, in the analysis, optimization and design of a number of industrial processes, focusing principally on casting technology. In the last 6 years I have received substantial support from industry for my effort as either the primary or co-investigator.
The expertise in heat transfer extends beyond the basics of heat conduction to include inverse conduction techniques, which have been applied to analyse complex industrial boundary conditions, solidification microstructure evolution in cast irons, freckle formation in nickel-based superalloys and hydrogen-based porosity formation in aluminum alloys . In the case of my thermal stress analysis activities, most of the effort has been directed toward the prediction of stress and strain evolution in casting processes with a view to reducing cracking and distortion and has involved both elastic and inelastic deformation. For example, a significant effort recently has been directed toward understanding and predicting the formation of hot tears in aluminum ingots that develop during the start-up phase of the direct-chill (DC) casting process and to understand mechanistically why some alloys are more sensitive to cracking than others (the DC casting process is the dominant industrial process used to produce aluminum sheet ingots).
Laboratory and industrial measurements continue to play a large role in my activities since, in many instances, the knowledge necessary to develop sophisticated process models does not exist within the literature. The data collected represents new knowledge and includes data related to heat transfer phenomena , data related to distortion phenomena data related to porosity formation, data related to the constitutive behaviour of alloys at high temperature, including in the semi-solid state , data related to defect formation in nickel-based superalloys and data related to the evolution in the solidification structure in various aluminum alloys . The collection of this data often represents a significant challenge and requires the use of sophisticated state-of-the art equipment and techniques. The industrial data in particular is often very difficult to acquire because of the need to work on production equipment, but is unique and often essential to our understanding of how these processes operate mechanistically.
As evidence of impact, many of the codes for which I have coordinated the development are actively in use by industry. Specifically, the code developed for Canadian Autoparts Toyota Inc. is being used in the design of die-tooling for the production of aluminum alloy wheels; the code developed for the TIMKEN Company is being utilized in the thermal-mechanical processing of steel tubing; and the code developed for Alcan Ltd. is being applied to optimize the casting recipe used during the start-up phase of the DC casting process. These are major international corporations with a significant impact on the global economy.
Primary collaborators: Dr. Daan Maijer (UBC), Dr. Mary Wells (Waterloo), Canadian Auto Part Toyota, Rio Tinto Alcan, The Timken Company.
MTRL 278 Engineering Materials
MTRL 340 Manufacturing in Materials Engineering
MTRL 515 Advanced Simulation and Modelling Tools for Materials Manufacturing
Refereed Journal Publications
Refereed Conference Proceedings