Tribological analysis of thermal spray coatings of ni and AL2O3 with dispersion of solid lubricants in wear modes

John V. Christy, Abdel Hamid I. Mourad, Sudhir Tiwari

Research output: Chapter in Book/Report/Conference proceedingConference contribution

14 Citations (Scopus)


In the present work, Ni and 60 wt. % of AL2O3, as thermal spray was mixed in 2:1 proportion with entrapped solid lubricant such as PTFE and Graphite through a D-Gun on the Bakelite used as substrate. For that, the specimen was taken and cleaned properly and coated with thermal spray and solid lubricating coatings of 0.5 micrometre thickness. At elevated temperatures, NiAL2O3 a common thermal spray coating protects the solid lubricants entrapped in it and thus causes the layer to be stable and dynamic. The solid lubricants mixed in thermal spray were graphite and PTFE. These were then ultrasonically cleaned in the acetone bath. The coating is done by a duo spray pump that spurts the coating on the work piece. This pump spurting is controlled by a semi permeable membrane coated on the work piece. Coatings were tested at different air pressure, temperature and impingement angle. It was found that the degradation of coating was observed on low impingment angles and also with the reciprocating stress inputs. The Graphite and NiAL2O3 coating is found to be more stable tribologically as compared to PTFE and NiAL2O3 coating at high temperatures and pressures. Morphological analysis of coatings was also done. The coating was tested on cutting tool ends like drill bits, planar cutting tool and turning tools. Separate analysis was carried out on erosive wear, abrasive wear, temperature and pressure with varied load conditions on the coatings done on Bakelite. On all the individual tests done Graphite and NiAL2O3 mix coating was found stable. This coating finds much more application in pipes and pressure vessels systems. The inside bore of a pipe can be coated similarly which will smoothly transfer the abrasive sludge or fluids with much reduction on its friction coefficient.

Original languageEnglish
Title of host publicationMaterials and Fabrication
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Electronic)9780791857991
Publication statusPublished - 2017
EventASME 2017 Pressure Vessels and Piping Conference, PVP 2017 - Waikoloa, United States
Duration: Jul 16 2017Jul 20 2017

Publication series

NameAmerican Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP
ISSN (Print)0277-027X


OtherASME 2017 Pressure Vessels and Piping Conference, PVP 2017
Country/TerritoryUnited States


  • Erosion
  • Solid lubricant abrasion pressure vessels pipes drill bit
  • Thermal coating
  • Wear

ASJC Scopus subject areas

  • Mechanical Engineering


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