Significant Research Contributions

1.Novel experimental methods for investigation of texture


At an early stage of his academic carrier Dr Szpunar proposed and developed a new neutron diffraction method for texture and stress investigation in metal sheets and other materials. He also proposed and implemented the application of neutron TOF method for texture investigation . These methods are now used in almost all nuclear research centers throughout the world. The methods were described in an extensive review (a) prepared for the International Atomic Energy Commission and distributed in all nuclear research centers associated with this agency.

The Nominee proposed also the application of energy dispersive diffraction to texture studies (b) and for the first time demonstrated this application.

2. Modeling and simulation of texture and microstructure


Dr. Szpunar pioneered the application of Pot?s methods of microstructure description for simulation of microstructural and textural evolution during annealing and electro-deposition processes. In particular he proposed new models of texture transformation during nucleation, recrystallization and normal or abnormal grain growth in industrial manufacturing processes. These models supported by experiments offered innovative approached towards fundamental understanding of microstructure and texture transformation of steels and aluminium alloys during annealing processes. The results obtained were presented in 10 Acta Materialia papers. Some of the concepts developed in this research were used to propose improvement of the process of manufacturing magnetic steels by Kawasaki Steel (Japan) and Posco (Korea).

3. Magnetism and crystallographic texture


Methods were developed that allowed explanation of texture influence on the magnetic properties of various hard and soft magnetic materials and perpendicular magnetic recording media. Also, a unique method was proposed to obtain from the neutron diffraction pole figure measurements the information about the distribution of magnetic moments in polycrystalline textured materials. This was the first time that such a distribution was obtained. This research was published in (e) Phys. Rev B. Development of the method for magnetic texture study might have important impact via better understanding of the magnetization processes in textured soft and hard magnetic materials. Various other innovative methods were developed by the applicant leading to a better understanding of correlation between texture and magnetic properties.

4. Development of methods for improvement of high temperature oxidation resistance


A new method based on a control of surface texture and application of reactive element coatings was applied to nickel and some nickel alloys. It was shown that the proposed method can improve the oxidation resistance by two orders of magnitude. The model of oxidation control was verified experimentally.

5. Oxidation and hydrogen ingress in Zr-Nb alloys


Pressure tubes in CANDU reactors are made of a zirconium alloy containing 2.5% niobium. One of the factors limiting the life of these components is hydrogen ingress and consequent hydride formation, leading to embrittlement and fracture. We have developed novel microstructural model of oxidation and oxide texture development (e,h) microscopic model of hydrogen ingress, identified novel structural transformation in zirconium oxide (a,b,l) and discover important correlations between texture of oxide and the rate of hydrogen ingress. The correlation proposed may be a unique tool for assessment the tube quality prior to installation for service, and for evaluation of potential risk of failure. Importance of this research is illustrated at best by the support obtained from AECL for three Strategic NSERC grants of the applicant. The results obtained can be extended to other Zr alloys that are major structural components of almost all nuclear reactors.

6. Electromigration Failure of Electronic Interconnects


Understanding a role of texture and grain boundary transport in Al-Cu traditional interconnects and Damascene processed Cu interconnects. We have for the first time analyzed details of surface and grain boundary diffusion and role of texture in the process of electromigration failure. We were able to identify the microstructural characteristics that are responsible for formation of hillocks and voids and to model the process of failure. This research was summarized in the chapter of a book entitled

7.Computational Material Science


Our aim is to combine the specific strengths in the fields of material science engineering and high-performance computing. Recently a team supervised by Dr. Barbara Szpunar initiated the project called QE_nipy to provide engineering students with a simple tool to run Quantum Espresso code and to obtain needed data. The complete, exemplary notebooks have been developed using ipython as described on the web site:

  • http://homepage.usask.ca/~bas627/nipy/Nipy.html.