A study of nanoindentation for mechanical characterization of chromium and nickel borides’ mixtures formed by laser boriding

Laser boriding is the process which improves the wear resistance of Inconel 600-alloy. During this treatment, the surface of base material is coated by paste, including amorphous boron. Then the surface is re-melted by a laser beam. As a consequence of the high overlapping of laser tracks (86%), the uniform laser-alloyed layer is produced, in respect of the thickness. It is easy to identify the mixture of chromium borides (CrB+Cr2B) as well as the mixture of nickel borides (Ni3B+Ni2B) in the microstructure of the re-melted zone by X-ray microanalysis using EDS. In this study, the mechanical properties of both chromium and nickel borides’ mixtures are examined using the nanoindenter with a Berkovich diamond tip. Youngʹs moduli and hardness are measured and compared with the literature data. The load–displacement curves and the indentation images are shown for the selected measurements. The higher average values of Youngʹs modulus (355.11 GPa) and hardness (28.25 GPa) characterize the chromium borides’ mixture. In case of the nickel borides’ mixture, the average Youngʹs modulus is equal to 287.91 GPa, and the hardness of 13.51 GPa is measured.