Residual stress is one of the main reasons for failure of automotive cylinder blocks and engine heads. These failures are typically associated with in-service distortion or cracking occurring in engines during operation cycles. The problem becomes more pronounced for engines that are running at elevated operating pressures and temperatures, limiting R&D options in developing and implementing higher-efficiency engines. New aluminum alloys and manufacturing methods have been introduced with varying degree of success, in many cases affected by the stress magnitudes and stress distribution in the component. Therefore, active research is ongoing internationally on finding the most reliable methods of stress analysis as a basis for developing efficient methods for stress mitigation. The current study presents a comparison between two experimental strain measurements techniques: a destructive method that is based on application of strain gauge sensors, and a non-destructive method using neutron diffraction. The results indicate that although the strain gauge method provides an indication of the nature (i.e. compression or tension) of strain within a component, this method should primarily be used for surface measurements and qualitative analyses only. Neutron diffraction remains the superior technique for strain analysis, particularly for engineering components with complex geometries. The results from this study provide the transportation industry with a more comprehensive understanding of the efficacy of utilizing strain gauge sensors, neutron diffraction or finite element modelling for measuring the residual strain in cast components. The results will help manufacturers to develop the next generation of powertrain systems with increased efficiency and improved performance.

Mathematical modelling has been widely used as a powerful tool for process design and optimisation of the continuous casting process. A three-dimensional heat transfer model was developed to simulate heat transfer and solidification in a horizontal billet continuous casting system. In this model, the air gap formation and its effect on heat extraction from the billet was also modelled and considered. The developed model was run to simulate the heat transfer and solidification for an industrial billet casting machine. The predicted temperature distribution within the mould and billet was compared with those measured on an industrial caster and good agreement was obtained. Parametric studies were carried out to evaluate the effects of different parameters on the temperature distribution and solidification profile within the cast brass billet. Finally, the secondary dendrite arm spacing (SDAS) was determined experimentally and a semiempirical correlation between measured SDAS and corresponding calculated cooling rate was proposed for continuously cast brass billet.

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