Electroless Ni-B and Ni-P coatings with high-fretting resistance for electrical contact applications

Dervos, CT; Novakovic, J; Vassiliou, P

dc.contributor.author	Dervos, CT	en
dc.contributor.author	Novakovic, J	en
dc.contributor.author	Vassiliou, P	en
dc.date.accessioned	2014-03-01T02:42:45Z
dc.date.available	2014-03-01T02:42:45Z
dc.date.issued	2004	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/31061
dc.subject	Chromium	en
dc.subject	Contact Resistance	en
dc.subject	Microstructures	en
dc.subject	Nickel	en
dc.subject	Phosphorus	en
dc.subject	Scanning Electron Microscope	en
dc.subject	Thermal Treatment	en
dc.subject	Heat Treatment	en
dc.subject.other	Adhesion	en
dc.subject.other	Chromium plating	en
dc.subject.other	Corrosion resistance	en
dc.subject.other	Electroless plating	en
dc.subject.other	Fretting corrosion	en
dc.subject.other	Heat treatment	en
dc.subject.other	Microhardness	en
dc.subject.other	Microstructure	en
dc.subject.other	Nickel compounds	en
dc.subject.other	Polarization	en
dc.subject.other	Recrystallization (metallurgy)	en
dc.subject.other	Contact resistance	en
dc.subject.other	Electric contact resistance	en
dc.subject.other	Linear polarization	en
dc.subject.other	Substrate materials	en
dc.subject.other	Electric contacts	en
dc.title	Electroless Ni-B and Ni-P coatings with high-fretting resistance for electrical contact applications	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1109/HOLM.2004.1353131	en
heal.identifier.secondary	http://dx.doi.org/10.1109/HOLM.2004.1353131	en
heal.publicationDate	2004	en
heal.abstract	Electroless nickel-phosphorus and nickel-boron plating has been tried on steel and brass substrates. By selected conditions of heat treatment in a high vacuum environment the plating can produce more than chromium equivalent hardness without the effluents of the hard chromium plating process. The resulting surfaces of Ni-P and Ni-B were examined and characterized under an optical and a scanning electron microscope. XRD analysis was also performed to investigate re-crystallization effects. The fabricated contact materials were also tested under corrosion conditions, and linear polarization measurements were performed. The electrical contact resistance of the deposits was also recorded during a 10,000 cycle test. The results show that after the heat treatment in a high vacuum environment the platings acquire a crystalline microstructure, with very good adhesion to the substrate materials (steel or brass). In addition, the microhardness of vacuum heat treated Ni-P coatings attained values of 1200 HV, while the nickel-boron coatings acquired an even higher microhardness, exceeding 1600 HV. The electrical performance of the fabricated layers showed that after thermal treatment the contact resistance remained almost unaffected. However, the Ni-B overlayers systematically exhibit lower contact resistance profiles. The above materials could be practically utilized whenever a good electrical performance of a hard engineering coating is required.	en
heal.journalName	Proceedings of the 50th IEEE Holm Conference on Electrical Contacts and the 22nd International Conference on Electrical Contacts	en
dc.identifier.doi	10.1109/HOLM.2004.1353131	en
dc.identifier.spage	281	en
dc.identifier.epage	288	en