Biotribological behaviour evaluation of the ISO 5832-1 stainless steel for biomedical applications treated by optical fiber laser

Abstract

The present study evaluated the influence of an optical fiber laser surface treatment process on the tribological behaviour of the ISO 5832-1 austenitic stainless steel (SS) on the coefficient of friction and coefficient of wear in ball-cratering wear tests. For comparison reasons, surfaces non treated by laser were also evaluated. A phosphate buffer solution (PBS) was used as electrolyte. Samples of this biomaterial were treated by alternating the laser frequency in order to find out a condition that improves its tribological behaviour. Micro-abrasive wear tests were carried out with a ball of AISI 316L SS (diameter of 25.4 mm – 1”), used as counter-body, and abrasive slurries prepared with abrasive particles of Al2O3 and distilled water. The sample’s surfaces finishing were analyzed by optical and electronic (SEM-EDX) microscopy. The surface characterization showed microstructure modification due to the high temperatures involved in the laser process and the micro-abrasive wear results indicated that the tribological behaviour is influenced by the frequencies values used for the laser surface treatment.