Stress and electrochemical corrosion of titanium produced by laser rapid forming / 中华口腔医学杂志

ABSTRACT

Objective@#To investigate the stress corrosion and electrochemical corrosion resistance of titanium produced through laser rapid forming (LRF), and to provide a basis for their clinical application.@*Methods@#Forged commercial pure titanium (CP-Ti) was used as control group and LRF pure titanium was used as LRF group. All samples were placed in acidic artificial saliva containing fluorine (pH=7), and loaded with a stress of 1.2 × σ0.2 Pa (σ0.2 represents the yield strength of material). Stress corrosion resistance of specimens that have been soaked for 30 days was analyzed by naked eye observation, X-ray diffraction analysis and scanning electron microscopy. For samples placed in artificial saliva, neutral fluoride solution (pH=7) and acidic fluoride solution (pH=3) (4 test pieces in each corrosive medium), and their electrochemical corrosion resistance was evaluated by free corrosion potential (Ecorr) measurements, corrosion current (Icorr), electrochemical impedance spectroscopy (EIS), and anodic polarization curves.@*Results@#With the prolongation of immersion time, the corrosion products gradually increased. The stress corrosion of CP-Ti group was significantly more than that of LRF-Ti group, and the pit diameter was significantly larger than that of LRF-Ti group. The electrochemical corrosion results showed that the Ecorr (-469 mV) of LRF-Ti in artificial saliva was higher than that of CP-Ti (-555 mV), and the Ecorr (-925 mV) of LRF-Ti was higher than that of CP-Ti (-943 mV) in neutral fluoride solution. In acid fluoride solution, the Ecorr (-943 mV) of LRF-Ti was higher than that of CP-Ti (-956 mV). The Ecorr of the same metal was the highest in artificial saliva and the lowest in acid fluoride solution; the Icorr of the same metal was the lowest in artificial saliva and the highest in acid fluoride solution.@*Conclusions@#Under the same corrosion conditions, LRF Ti demonstrated better stress and electrochemical corrosion resistance than CP-Ti.