Microstructural and Chemical Analysis of AgI Coatings Used as a Solid Lubricant in Electrical Sliding Contacts
2012 (English)In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 46, no 2, 187-193 p.Article in journal (Refereed) Published
AgI coatings have been deposited by electroplating on Ag-plated Cu coupons. Electron microscopy shows that the coatings consist of weakly agglomerated AgI grains. X-ray diffraction, differential scanning calorimetry, thermogravimetry, and mass spectrometry show that the AgI exhibits a reversible transformation from hexagonal to cubic phase at 150 A degrees C. AgI starts to decompose at 150 A degrees C with an accelerating rate up to the AgI melting temperature (555 A degrees C), where a complex-bonded hydroxide evaporates. Ag pin-on-disk testing shows that the iodine addition to Ag decreases the friction coefficient from 1.2 to similar to 0.4. The contact resistance between AgI and Ag becomes less than 100 mu I (c) after similar to 500 operations as the AgI deagglomerates, and Ag is exposed on the surface and remains low during at least 10,000 reciprocating operations. This makes AgI suitable as a solid lubricant in electrical contacts.
Place, publisher, year, edition, pages
Springer Verlag (Germany) , 2012. Vol. 46, no 2, 187-193 p.
Silver iodide, Friction coefficient, Contact resistance, TEM, Phase transformation, DSC
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-76935DOI: 10.1007/s11249-012-9938-3ISI: 000302251500010OAI: oai:DiVA.org:liu-76935DiVA: diva2:524591
Funding Agencies|VINNOVA VINN Excellence Centre in Research and Innovation on Functional Nanoscale Materials, FunMat||2012-05-032012-04-272016-08-31