Evaluation of Modified Ti-6Al-4V Implant Surface Through β-Tricalcium Phosphate by Using Additive Mixed Electrical Discharge Machining for Biomedical Application.

Ti-6Al-4V alloy due to high mechanical properties and high corrosion resistance is widely used in the manufacture of biomedical devices, including hip articulations, screws and dental implants. For proper implant performance in the long run, a rapid reaction between the bone and implant should be performed, which depends on the surface properties of the layer doped on the surface of the implant. The surface coating is therefore considered to be the underlying factor in the attenuation of such occurrences. This research aims to assess the modified surface of Ti-6Al-4V by the mixed electric discharge (EDM) process of β-tricalcium phosphate powder to detect potential bioimplants. One of the features of this coating process is the location of the base titanium layer containing β-tricalcium phosphate, thereby improving the substrate properties. For investigating the surface morphology, distribution and dispersion of elements on the modified surface, field emission scanning electron microscope (FE-SEM), energy-dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD) tests were used. Morphological features have shown that porous surface topography just like natural bone is coated on the surface of Ti-6Al-4V alloy using the AM-EDM process. EDS and XRD examinations showed the coated layer compositions from Ti kα, V, Al, Ca and P and also formation of the biocompatible phases such as Ca 2 P 2 O 7 andCa OH 2 on the surface of Ti-6Al-4V, which caused the better biocompatibility of the alloy, creation of an antibacterial agent for periodical injuries and also improvement of the bone formation on the alloy surface. The results also showed that the size of the resin thickness was 35 micrometers, which contained nanoparticles of tricalcium phosphate, as well as an excellent metallurgical substrate with a strong bond between the substrate and the coating. In this research, the effects of input parameters, such as spark energy and powder concentration on output parameters, including material removal rate, surface roughness and surface hardness, were studied. The results showed that this method has a positive effect on the reduction in the material removal rate, roughness and hardness of the surface of the workpiece. Due to the dispersion of β-tricalcium phosphate particles, the surface roughness diminishes during the electric discharge process. Also, the highest material removal rate occurred in 21 A, the pulse duration of 50 μs and the concentration of 8 g/L, and minimal surface roughness occurred in 6 A, the pulse duration of 100 μs and the concentration of 4 g/L. The hardness of the surface deposited with β-tricalcium phosphate powder is 348 VH, which is 1.75 times more than the original surface. The reason is that the hard oxide is deposited on the surface of the workpiece. [ABSTRACT FROM AUTHOR]