Assessment of the Surface Characteristics of ISO 5832–1 Stainless Steel for Biomaterial Applications

Marking techniques are employed to ensure identification and traceability for biomedical materials. The present study evaluated the influence of laser and mechanical marking processes on the tribological behavior of ISO 5832-1 austenitic stainless steel (SS) regarding corrosion resistance, friction coefficient, and wear volume in ball-cratering wear tests. The laser marking process was performed using a nanosecond Q-switched Nd: YAG laser. Cytotoxicity tests were analyzed to assess the biomaterial’s biocompatibility. For comparison, non-marked surfaces were also evaluated. A phosphate buffer saline solution (PBS) served as both a lubricant and corrosion electrolyte. The surface finishing of the samples was analyzed using optical microscopy and scanning electron microscopy with a field emission gun (SEM-FEG) coupled with an energy dispersive X-ray spectrometer. The oxide layer was assessed by X-ray photoelectron spectroscopy (XPS). Wear tests were conducted for 10 minutes with PBS drops applied every 10 seconds at a frequency of 75 rpm; solid spheres of AISI 316L stainless steel (SS) and polypropylene (PP), each with a diameter of 1 inch, were utilized as counter-bodies. Corrosion resistance was evaluated using electrochemical methods. The results indicated variations in roughness and microstructure due to laser markings. The tribological behaviour was influenced by the type of marking process, and the wear rate depended on the normal force and the type of sphere. None of the samples were considered cytotoxic, although the laser-marked surfaces showed the lowest cellular viability among the tested surfaces and the lowest corrosion resistance.