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Al2O3/TZ-3YS coatings developed by suspension plasma spraying were studied in the present work. Mechanical and thermal characterization was realized to evaluate the suitability of thermal barrier coatings. In addition, SiC particle reinforcement was evaluated for its effect on the mechanical properties of the coating. The problem with SiC reinforcement is its high melting point that causes a large amount of unmolten material to be deposited on the coating. One possible solution followed in the present study consists of including fructose as an additive in order to modify the suspension characteristics. The results conclude that the use of fructose as an additive increases the mechanical and thermal properties (from 1.0 to 1.6 W/m·K), since the microstructure is modified, and results in a lower porosity (17%) compared to the SiC coating (25%). [ABSTRACT FROM AUTHOR]

Today, in industry, laser-based additive manufacturing (LAM) is used to produce high-value parts of very complex designs that are not manufacturable by conventional technologies; this process' low production throughput and high cost prevent it from being used more extensively. One way to exploit the benefits of LAM in industry is to have it combined with lower-cost manufacturing technologies. In a hybrid approach, LAM can be integrated within an assembly line's welding station to complete the manufacturing of a product by depositing a foreign material on a substrate only where needed, or by building structures of complex 3D geometries (e.g., lattice structures) directly onto inexpensive preforms. To pave the way for using a hybrid approach design in real applications, as a prime requirement, the chosen technology must grant comparable structural integrity to its products with respect to its conventional counterparts. In this work, different types of surface pretreatments for substrates were investigated as a key enabling factor to tailor the bi-material system's mechanical properties in use. Hybrid samples were made by depositing AlSi10Mg by direct metal laser sintering onto A356-T6 aluminum bases prefabricated by casting and forging, and their properties were compared with fully homogeneous samples that were conventionally produced. Specifically referring to the automotive use case, both these alloy grades were chosen for their extensive use in the production of motor vehicles. The testing campaign, characterized by microscopy, mechanical testing, and fatigue, revealed that the structural integrity of the hybrid samples is comparable with the benchmarks when standard heat treatments are adopted. This result makes the prospect of the exploitation of the hybridization concept as conceived very promising for the future. [ABSTRACT FROM AUTHOR]