The peculiarity of abrasiveness of a galvanic iron binder of an abrasive tool
Închide
Articolul precedent
Articolul urmator
554 0
SM ISO690:2012
BORTSOI, Tudor. The peculiarity of abrasiveness of a galvanic iron binder of an abrasive tool. In: Materials Science and Condensed Matter Physics, Ed. 7, 16-19 septembrie 2014, Chișinău. Chișinău, Republica Moldova: Institutul de Fizică Aplicată, 2014, Editia 7, p. 314.
EXPORT metadate:
Google Scholar
Crossref
CERIF

DataCite
Dublin Core
Materials Science and Condensed Matter Physics
Editia 7, 2014
Conferința "Materials Science and Condensed Matter Physics"
7, Chișinău, Moldova, 16-19 septembrie 2014

The peculiarity of abrasiveness of a galvanic iron binder of an abrasive tool


Pag. 314-314

Bortsoi Tudor
 
Institute of Applied Physics, Academy of Sciences of Moldova
 
 
Disponibil în IBN: 21 martie 2019


Rezumat

Technology of fixation of ceramic or diamond particles using the galvanic metals are extensively used in manufacturing grinding discs, drills, taps, milling cutters, etc. The tools based on a galvanical binder have a lower cost, higher cutting capacity and processing accuracy compared to those produced by the sintering method. One galvanic binder which is characterized by high physicomechanical properties is an iron binder. The technology of its formation is highly efficient, environmentally compatible and simple in putting into practice. However, the application of it for the creation of the abrasive tools is not sufficiently widespread.      Evidently, its abrading capacity has not yet been studied adequately, in particular, concerning the tribocontact with high-strength and abrasive surfaces.   In this context, the abrading capacities of various iron galvanical binders were studied during their friction-sliding motion against a hard abrasive surface. The methods of estimation and parameters of the friction mode were selected on the basis of the standard values in tribotechnics for such kind of abrasive tests.  The testing showed that depending on the intensity, pure iron has the highest coefficient of friction against an abrasive surface based on the ceramic binder. The coefficient of friction of the galvanic iron doped with cobalt and nickel is significantly less. Moreover, the cobalt-doped galvanic iron has the lowest coefficient of friction as a consequence of the tribocontact load. The relative partial coefficient of friction of pure iron is the lowest, and with respect to the normal load, it is about 30--43% of the friction coefficient of the contact. The nickel-doped galvanic iron has the highest relative partial coefficient of friction and, depending on the load of friction, it is about 70--95% of the friction coefficient of the contact. The relative partial coefficient of friction of the cobalt-doped galvanic iron is about 70--80%. Here, the grains of the abrasive surface are abraded far more during the friction against the surface of pure electrochemical iron than against the surfaces doped with nickel or cobalt. At the same time, separation of the abrasive grains from the ceramic binder occurs at much less loads during the friction against the pure galvanic iron than against the doped iron. For the galvanic iron with a tribocontact surface screened using the dispersion phase (DP) M7, the friction coefficient depends on the fraction of the screened surface by the DP particles and the load of testing. At the same time, the friction coefficient of the tribocontact is the highest with the 33% screened surface, which exceeds significantly the values 14.3% and 41.6% of the friction coefficient of the tribocontact of the screened surfaces. The relative partial coefficient of friction of the 33% screened iron deposit is the most stable with respect to the tribocontact load.  Evidently, owing to the friction forces, the near surface layers of galvanic iron are exposed to the elastic-plastic deformations, nucleation, fracture propagation and destruction. In addition, in the near surface layers, depending on the conditions of friction, the processes occur which can either strengthen or weaken them, and the DP in the galvanic iron significantly affects these processes [1].  Thus, as a result of the study of the abrasiveness of the galvanic iron it was inferred that pure iron forms the highest adhesive forces at the tribocontact with the abrasive surface. The elastic properties of the near surface layers of the galvanic iron with DP depend on the extent of screening