US EPA

4838477 

Journal Article 

Tribological behavior of sodium borohydride reduced electroless nickel alloy coatings at room and elevated temperatures 

Mukhopadhyay, A; Barman, TK; Sahoo, P 

2017 

1 

Surface and Coatings Technology
ISSN: 0257-8972 

321 

464-476 

10.1016/j.surfcoat.2017.05.015 

WOS:000405881900053 

The present work investigates and compares the tribological behavior of sodium borohydride reduced electroless Ni-B, Ni-B-W and Ni-B-Mo coatings at room temperature (25 degrees C), 100 degrees C, 300 degrees C and 500 degrees C A typical nodulated surface morphology with amorphous structure is observed for the EN binary and ternary alloy coatings. Deposition of W along with Ni-B results in improved microhardness and tribological behavior at room temperature, 100 degrees C and 300 degrees C along with excellent thermal stability. But the highest resistance to wear is exhibited by Ni-B-Mo coatings at 500 degrees C test temperature due to a protective tribo-oxide layer formation consisting of oxides of nickel and molybdenum. Depending on the test temperature, the wear mechanism is also seen to vary with the tribological behavior being controlled by in-situ phase transformation, formation of tribo-oxide layers as well as mechanically mixed layers. (C) 2017 Elsevier B.V. All rights reserved. 

Electroless; Ni-B; Ni-B-W; Ni-B-Mo; Wear rate; COF; High temperature