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International audience; This research is conducted on the IN625 superalloy as a substrate fabricated by selective laser melting method, which is coated with bond coat. The microstructure and chemical composition are investigated using optical microscopy and Field Emission Scanning Electron Microscopy (FE-SEM) coupled to an Energy Dispersive Spectroscopy (EDS) detector. The bond coat and substrate present a homogeneous microstructure, strong metallurgical bond and good adherence between substrate and bond coat. Moreover, the microstructure is difficult to distinguish between the bond coat and substrate using optical microscopy. Furthermore, the selective laser melting has a low level of Oxygen, indicating a low diffusion and oxidation rate during manufacturing process.

In this work, the effect of chitosan and CaCO3 coating on polyurethane (PU) foam on the mechanical and thermal properties was studied. PU-foams were soaked in a mixture of chitosan- calcium carbonate solution at different concentrations, i.e., 0.1–0.4%. The molecular behaviors due to the incorporation of chitosan/CaCO3 into the PU-foam matrix were investigated by Fourier-Transform Infrared (FTIR) spectroscopy. Field Emission Scanning Electron Microscope (FE-SEM) was utilized to study the effect of chitosan/CaCO3 coat on the pore structure of PU-foam. FTIR spectra show changes in the peak of 1446 and 1413 cm–1, which serve as evidence of molecular interaction between PU and chitosan/CaCO3. FE-SEM images show that the addition of chitosan/calcium carbonate cells was starting to close together, probably due to the increased dispersion of calcium carbonate on the entire surface of PU-foams/chitosan, which indicates that reducing the size of the cell will increase mechanical properties. From this study, it was found that PU-foam soaked in 0.4% CaCO3 had the highest tensile strength. Coating PU-foam with 0.4% CaCO3 also improved its thermal stability, indicated by an increase in its residual mass compared to neat PU-foam.