A wear test mimicking the tribological situation in rock drilling
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
This thesis work is performed at Sandvik Mining Rock Tools, a world leading supplier of rock drilling tools. The work is part of developing a new tribological wear test method for cemented carbide drill bit inserts. The test method has earlier been judged successful in mimicking the rotary-percussive rock drilling process because it gives the same wear mechanisms as have been observed for inserts used in rock drilling.
During testing the cemented carbide drill bit insert is pressed against a moving rock surface while water and particles are added to the contact area. The particles are present to simulate the rock crushings formed during drilling. They are believed to cause abrasive wear of the inserts. In this work the effect of load, particle material and particle size are studied. When adding silica particles, which are softer than the cemented carbide material, no correlation is obtained between wear rate and load or particle size. Cracking of WC grains, added rock material and removal of pieces of carbide material are seen at the worn sample surfaces. These observations are similar to observations described in other works about wear of cemented carbide. Adding alumina particles, which are harder than the sample material, gives high wear rate and ground/striped sample surfaces. The wear rate increases with alumina particle size.
Place, publisher, year, edition, pages
2012. , 45 p.
UPTEC K, ISSN 1650-8297 ; 12 007
tribological testing, wear test, cemented carbide, rock drilling
IdentifiersURN: urn:nbn:se:uu:diva-176977OAI: oai:DiVA.org:uu-176977DiVA: diva2:538551
Master Programme in Chemical Engineering
Jacobson, StaffanBerger, Rolf