Formation of Electroless Ni-B Coating on Boron Carbide Particles for Composite Processing

Abstract

The present investigation is on formation of a uniform coating of Ni-B coating on the surface of B4C particle by electroless technique by varying process parameters and pH of the coating bath. The coating characteristics observed on majority of pH conditions on activated particles were mesh-like and at higher pH 12 the coated surface characteristics changes to patch like morphology. At lower alkaline condition there was not enough time for co-deposition to occur and the co-deposits appeared along with the coated particles. The studies with varying pH showed that pH 8 gives uniform coating of the entire particles surface with Ni-B and above which higher amount of co-deposited particles of Ni-B is also observed.

Metallic composite coatings by electroless technique – a critical review

“…Surface activation of ceramics and polymers provide wettability of the surface as a prerequisite for subsequent void-less covering and good adhesion of metal layers. The surface cleaned particles or substrates are sensitised with Sn +2 ions followed by activation with Pd +2 to enhance the bondability between ceramic/polymer phases and metallic ions [18]. The activation process can be represented by the following equation; …”