Surface degradation mechanisms of cemented carbide drill buttons in iron ore rock drilling
2017 (English)In: Wear, ISSN 0043-1648, E-ISSN 1873-2577Article in journal (Refereed) In press
The wear behavior of cemented carbide rock drill buttons is influenced by many factors, which include the composition and microstructure of the cemented carbide material, the nature of the rock material, and the conditions of the rock drilling operation. Depending on the type of rock and on the drilling procedure used, the cemented carbide is exposed to substantially differing mechanical and thermal conditions. In the present study, the surface degradation and wear mechanisms of cemented carbide drill buttons exposed to iron ore rock drilling have been characterized based on a combination of high resolution scanning electron microscopy (SEM), focused ion beam cross-sectioning (FIB), energy-dispersive X-ray spectroscopy (EDS) and electron back scatter diffraction (EBSD).The results show a significant difference in surface degradation and wear between the front and peripheral buttons of the drill bits. While the front buttons display a relatively smooth worn surface with shallow surface craters the peripheral buttons display a reptile skin pattern, i.e. plateaus, 200-300. μm in diameter, separated by valleys, typically 40-50. μm wide and 15-30. μm deep, The reptile skin pattern is obtained in regions where the peripheral buttons are in sliding contact against the drill hole walls and exposed to high surface temperatures caused by the frictional heating. The results indicate that the reptile skin pattern is related to friction induced thermal stresses rather than mechanical contact stresses, i.e. the reptile skin pattern is formed due to thermal fatigue, rather than mechanical fatigue, caused by the cyclic frictional heating generated at the cemented carbide button/iron ore interface.
Place, publisher, year, edition, pages
Elsevier Ltd , 2017.
Cemented carbide, Iron ore, Reptile skin, Rock drilling, Wear mechanisms, Atmospheric temperature, Carbide tools, Carbides, Degradation, Drills, Energy dispersive spectroscopy, Fasteners, Friction, Ion beams, Iron, Iron ores, Ores, Photodegradation, Rock drills, Rocks, Scanning electron microscopy, Stresses, Tribology, Wear of materials, X ray spectroscopy, Cemented carbides, Electron back scatter diffraction, Energy dispersive X ray spectroscopy, High-resolution scanning electron microscopies, Mechanical contact, Surface degradation, Surface temperatures
Research subject Steel Forming and Surface Engineering
IdentifiersURN: urn:nbn:se:du-24700DOI: 10.1016/j.wear.2017.03.004ScopusID: 2-s2.0-85015717944OAI: oai:DiVA.org:du-24700DiVA: diva2:1087893