INVESTIGADORES
FAILLA Marcelo Daniel
artículos
Título:
Friction and wear behavior of irradiated polyethylene sliding against rough steel surface
Autor/es:
WALTER TUCKART; ERICA MOLINARI; DANIEL ROSSIT; M.D. FAILLA
Revista:
TRIBOLOGY LETTERS
Editorial:
SPRINGER/PLENUM PUBLISHERS
Referencias:
Lugar: New York; Año: 2014
ISSN:
1023-8883
Resumen:
The
aim of this study was to evaluate the tribological behavior of polyethylene
crosslinked by gamma radiation sliding against steel surface. Two high-density polyethylenes
were irradiated to total
dose in the range from 2 to 20 Mrad
under vacuum and at room temperature. After irradiation, the materials were annealed at 423 K and then cooled slowly to room temperature. The same thermal
treatment was applied to the non-irradiated
polymer.
The wear behavior of the polymers was determinedunder controlled ambient temperature of 298 K and 333 K using ahomemade tribometer. Sheet-shaped specimens were loaded against the
surface of a steel disc with different normal loads to generate nominal contact
pressures in the range of 0.25 to 1.5 MPa. The tests were performed under dry
conditions using a disc rotation to produce an average sliding
speed of 0.6 m/s, and during a period of time to provide an average sliding distance
of 1884 m. The wear rate was obtained as the mass loss by the sample divided
by the sliding distance, and the
friction coefficient was determined by measuring the friction force.
The
results indicate that the wear rate increases with load in the case of
non-irradiated polyethylene and low-dose irradiated polymers, while the wear
rate reaches a maximum value with the load in the case of the irradiated
samples with high doses. The samples irradiated with a dose of 10 Mrad showed
the lowest wear.
The
coefficient of friction increases slightly with the load in all the cases. Most
irradiated polymers shows higher coefficient of friction than the non-irradiated
material when compared at a given load. The results show that the
irradiation dose applied to the polyethylenes produced no noticeable effect on
the values of coefficient of friction when a comparison is done at a given
applied load.