Abstract
This study is an effort to investigate the synergic effect of nano-diamond (ND) addition and plasma nitriding (PN) treatment on tribological and structural properties of nickel-boron (NiB) coatings. NiB/ND nanocomposites containing different amounts of NDs (0.0, 0.1, 0.5, and 1.0 g/L) were produced in an electroless bath. Then, plasma nitriding was conducted on the samples for 1 h at 400 ?degrees C in an N-2-H-2 environment. To study phase analysis and examine the surface morphology of the samples, X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) were utilized. The wear behavior and friction were determined under the normal load of 10 N using the pin-on-disk method. The surface roughness, microstructure, and microhardness were also assessed. The results showed that, as the ND concentration increased, the amorphous structure of as-plated (AP) Ni-B transformed to a semi-crystalline one. Moreover, the amorphous structure of the as-deposited NiB/ND coatings changed to a crystalline one after plasma nitriding, which resulted in a higher hardness value. NiB/0.5ND coating showed the highest hardness value (1523 HV0.1) and the highest wear resistance (0.8x10(-10) Kg/ N.m). The smoothest wear trace with no visible cracks is related to the worn surface of PN NiB/0.5ND sample, suggesting that the NiB/ND nanocomposite can be a promising candidate for surface engineering processes.
NSTL
Elsevier