Effects of the Dynamic Tapping Process on the Biocompatibility of Ti-6Al-4V Alloy in Simulated Human Body Environment

摘要

The use of biomaterials depends on the high quality of the manufacturing and processing technology.Thus, the goal of this study is to contribute to the field ofmanufacturing of biomedical devices used in the human body. The forming and machining microtapping process (M3 thread and pitch 0.5mm) in Ti-6Al-4V alloy was investigated. The design of experiments (DoE) was performed to identify the effects of factors (speed and type of process) on the thrust force, torque, and ultra-microhardness. The biocompatibility of the formed and machined thread surfaces was evaluated through potentiostatic polarization and electrochemical impedance tests. A simulated body fluid was used as the electrolyte. The experimental results showed that the rate of passivation of titanium alloywas highest for machined threads. Furthermore, the low level of speed (2 m/min) presented better surface finish and more complete fill rate of thread profile.