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Additive manufacturing methods like Wire-Arc Additive Manufacturing (WAAM) open a new field to reduce manufacturing costs and minimising waste for various components in the civil engineering and construction sector. High deposition rates and lack of limitations in large, complex build sizes promote WAAM over other metal additive manufacturing technologies for this sector. Furthermore, the ability to produce novel and individual geometries of structural parts enable unseen design possibilities for architects, and potential structural and corrosive improvements in critical areas are unique properties of additive manufacturing. Currently, the lack of studies and standardisation is holding this technology back from finding a broad industrial application. Especially the insufficient knowledge of the residual stress state within build components in both experimental and simulations. Expecting a strong texture with large grain sizes, this research evaluates the residual stress state utilising the contour method. Special focus is given on the influence of data processing during the analysis to provide recommendations and in consequence improve understanding of residual stress measurement challenges arising with large-scale WAAM components. [ABSTRACT FROM AUTHOR]

Zirconium diboride (ZrB2), an ultra-high temperature ceramic (UHTC) is characterised by its combination of metallic and covalent bonding which confers high strength and a high melting temperature (>2500°C). These thermo-physical-mechanical properties coupled with the strong covalent bonding and low intrinsic self-diffusivity result in excellent high-temperature performance suitable for various energy, space, and defence applications; however, owing to these characteristics, UHTCs typically require elevated temperatures and pressures for consolidation. This work investigates the effect of consolidation temperature and dwell time on the microstructural development and density of zirconium diboride (ZrB2) fabricated via spark-plasma sintering (SPS). It was observed that increasing consolidation temperatures resulted in higher bulk densities (72.2% (1900°C), 95.2% (1950°C), 96.4% (1980°C), and 97.1% (2000°C)). Poor densification at 1900°C was attributed to insufficient thermal energy limiting gain boundary and lattice diffusion and grain boundary sliding whilst beyond 1950°C, density appeared to stabilise accompanied by residual intragranular porosity arising from grain coarsening. Extended dwell times at a lower temperature (1900°C), resulted in increased density, but substantial residual apparent porosity was measured (16-20%) for dwell times of 5 min, 10 min, and 20 min. At a higher temperature (1950°C), this effect diminished with modest (<0.5%) density increases for longer dwell times. Elevated temperatures had a more pronounced effect on densification compared to extended dwell times due to the former's impact on enhancing diffusion mechanisms. [ABSTRACT FROM AUTHOR]