Characterization of the virgin and recycled nickel alloy hx powder used for selective laser melting

Paper in proceeding, 2016

Taking to account high specific surface area of the powder, its surface state becomes one of the most important aspects of usability of the powder in PM process and particularly in additive manufacturing. Powder surface characterization of the two HX Ni-based superalloy powders sampled during selective laser melting-namely virgin and re-cycled powders was performed by means of XPS and high-resolution SEM combined with EDX. Results showed slight difference in surface chemical composition between the powders. The most sensitive to oxidation alloying elements in the powder-Al and Cr-segregate to the surface to form more stable oxides in case of re-cycled powder. Loss of silicon due to sublimation was also detected on the surface of re-cycled powder. Ni, as a base element, was presented in the form of hydroxide on the as-received surface of both investigated powders.