Chapters authored
Electrochemical Characterization of an Optical Fiber Laser- Treated Biomaterial
The implant manufacturing process includes texturization to enhance its adhesion and marking the final products for their identification, long-term quality control and traceability. Marking is carried out after cleaning and prior to sterilization. These marks eventually can concentrate stress leading to premature failure. The marked areas are defective regions that affect the passive film formed on the metallic biomaterials used for implants favoring the onset of various corrosion types, such as pitting, crevice or fatigue. This study aims to evaluate the effect of a Yb optical fiber laser marking processes used for metallic implants on the localized corrosion resistance of the austenitic stainless steel ISO 5832-1. This is one of the most used materials for manufacturing implants. The electrochemical behavior of the marked areas obtained by this method was evaluated in a phosphate-buffered saline (PBS) solution with pH of 7.4 and the results were compared with unmarked samples. All tested surfaces were prepared according to the recommendations for the use in surgery. For localized corrosion resistance evaluation, electrochemical tests such as monitoring the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and cyclic potentiodynamic polarization measurements were performed. The results showed that the laser marks affect the protector characteristics of the biomaterial’s passive film. Lower pitting resistance was associated to the laser marked areas.
Part of the book: Biomaterials
Evaluation of the Biotribological Behavior and Cytotoxicity of Laser-Textured ISO 5832-1 Stainless Steel for Use in Orthopedic Implants
This chapter evaluated the influence of laser texturing process on the tribological behavior of the ISO 5832-1 austenitic stainless steel (SS). The friction coefficient and wear were determined using ball-cratering wear tests. The laser texturing process was carried out with a nanosecond optical fiber ytterbium laser at four different pulse frequencies. Cytotoxicity tests were carried out to determine if laser texturing affects the biomaterial biocompatibility. For comparison reasons, pristine surfaces were also evaluated. The results indicated that the wear volume and friction coefficient were reduced after laser texturing. The samples were considered noncytotoxic according to the biocompatibility tests as the laser texturing process did not decrease cell’s viability.
Part of the book: Tribology, Lubricants and Additives