A study on the effect of reducing agent content on the thickness of electroless Ni3P deposits on B4C nanoparticles

Deposition of Ni3P nano-scale layer on B4C nanoparticles in four contents of sodium hypophosphite as reducing agent including 5, 10, 15 and 30 g/l via electroless coating were done to investigate the effect of reducing agent content on the coating thickness of deposited Ni3P. The bath pH and temperature was 5.5 and 85 degrees C, respectively and the coating time was 25 min. The powders were characterized by transmission electron microscopy (TEM) and the phases present were revealed by X-ray diffraction (XRD). Nickel and phosphorous contents of the coatings were measured by inductively coupled plasma analysis (ICP). The results revealed that by increasing the reducing agent content from 5 g/l to 30 g/l the average coating thickness increased from 19 nm to 28 nm. Although the increasing effect of adding sodium hypophosphite content was preserved, there is a critical amount for sodium hypophosphite content to increase the coating thickness.