List of Abstracts 2022: PLENARY SESSION

This talk will cover brief introduction of both materials research at University of Manchester and surface engineering group at Institute of Materials, Mining and Minerals, UK. Then the talk will present study of coatings at University of Manchester in collaboration with Rolls-Royce. Thermal barrier coatings (TBCs) have been applied to aero-engine components to protect the metallic components from aero-engine environments. While understanding and predicting failure of TBCs is critical for application of TBCs in aero-engines, the failure mechanisms of TBCs in engine environments is very complicated. This talk will cover various studies of TBCs with focus on characterisation of TBCs using various analytical tools at University of Manchester. The characterisation study has been used to understand residual stresses, mechanical property and microstructure of TBCs after exposure to engine environments. In addition, coatings for protection of Ti alloys will be examined for aero-engine applications.

The existing knowledge on the use of alloying additives in the zinc bath was analyzed. The appropriate content of alloying additives in the bath affects the quality of the coatings and also optimizes the consumption of zinc. Al and Ni are currently used as standard bath alloying additives. Zinc baths also contain Pb, Bi and Sn, interchangeably used, as standard. These metals improve the fluidity of liquid zinc, which results in a beneficial reduction of zinc consumption and improves the appearance of the coating. However, the presence of Pb in the bath should be limited due to its toxicity, while Bi and Sn increase the risk of liquid metal embrittlement (LME). These metals can also contribute to lowering the corrosion resistance of coatings. An alternative to the currently used baths containing Pb, Bi or Sn can be a bath containing only the addition of AlNi.
The article specifies the optimal concentration of Al and Ni addition for the bath. The synergistic effect of AlNi addition on the kinetics of coatings growth in the temperature range of 440-460oC was determined. The microstructure was disclosed and the chemical composition in the micro-areas of the coatings on low-silicon steel and on steel from the Sandelin range was determined. It was found that the synergistic effect of the optimal AlNi additive content allows to obtain coatings with the correct appearance and thickness meeting the requirements of EN ISO 1461. The AlNi content effectively reduces the reactivity of Sandelin steel. The coatings obtained in the bath containing only the AlNi additive have a similar structure and thickness to the coatings obtained in the alternative baths containing Pb, Bi or Sn.