ISSN 1070-4272, Russian Journal of Applied Chemistry, 2014, Vol. 87, No. 4, pp. 514−517. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © Yu.V. Prusov, V.F. Makarov, 2014, published in Zhurnal Prikladnoi Khimii, 2014, Vol. 87, No. 4, pp. 524−527.
AND POLYMERIC MATERIALS
Electroless Deposition of Ni,B-containing Coatings
Yu. V. Prusov and V. F. Makarov
Alekseev State Technical University, ul. Ul’yanova 1, Nizhni Novgorod, 603005 Russia
Received February 13, 2014
Abstract—Variation of pH of the solution and introduction of various additives signiﬁ cantly inﬂ uences such
properties of the deposited coatings as microhardness, wear resistance, anodic activity, and solderability. Based
on the results obtained, solutions for preparing coatings with preset functional properties were developed. The
solutions were tested and brought into practice at a number of enterprises.
Owing to advantages of nickel alloys such as enhanced
microhardness and wear resistance, good solderabil-
ity and microweldability, corrosion resistance, and low
contact resistance and volume resistivity, coatings made
of them are demanded by microelectronics and other
branches of engineering and industry.
Nickel alloy coatings on various surfaces can be
deposited by different procedures [1, 2], in particular,
by deposition from hot aqueous solutions with various
reductants [hydrazine, hypophosphite, borohydride, for-
malin, dimethylaminoborane (DMAB)].
The requirements to such coatings can be met by de-
positing alloys of various compositions and structures.
These and other characteristics can be controlled by vary-
ing the solution composition and deposition conditions.
To this end, it is necessary to know the mechanism and
relationships of the process [3, 4].
The goal of this study was to examine how ionic,
nonionic, and powdered additives introduced into an
electroless nickel plating solution inﬂ uence the compo-
sition and properties of the deposited Ni–B alloy ﬁ lms.
We considered pure Ni–B alloys and alloys with
various additives, deposited by electroless plating in
the form of ﬁ lms on pretreated steel samples from a
solution containing DMAB as reductant and having the
following composition (g L
O 20, NH
O 40, and DMAB 2; pH 7–8,
temperature 70–75°. The coating deposition rate was
calculated from the sample weight gain. The adhesion
was measured from the sample weight loss after mak-
ing a grid of scratches with a step of 1 mm on an area
of 1 cm
. The coating that peeled off was removed with
a brush, and the weight loss was measured. The micro-
hardness was measured with a PMT-3 microscope at an
indenter load of 50 g. The solderability was evaluated by
the spreading coefﬁ cient of POS-60 solder (FKDT ﬂ ux)
in accordance with the State Standard . The speciﬁ c
and contact resistance of coatings and their boron content
were measured by the procedures described in .
Below are the properties of Ni–B coatings deposited
at a rate of 8.4 m h
Microhardness, kg mm
Volume resistivity, mm
Boron content, %
Total content of impurities, %
The electrical characteristics of Cs-containing Ni–B
coatings are given in the table.