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Go to Editorial ManagerThe microstructural analysis and electrochemical measurements tests were used to investigate the behaviors of (TiO2) and (HAp)-coated Ti-6Al-7Nb alloy in the SBF solution .By using RF sputtering, a thin TiO2 layer coated the substrate, while a thick layer of HAp coated the outer side of surface. The generated middle layer consist of the composite of TiO2 and HAp which is by AFM characterized as uniformly distributed coating system with nano size. The images of the scan electron microscopy (SEM) shows that there is no any cracking observed in the outer layer of tested samples due to the use of thin film TiO2 as mid lead to reduce the difference in the thermal expansion between the HAp material and Ti-6Al-7Nb substrate .The HAp upper layer significantly improve the bioactivity of the Ti-6Al-7Nb alloy. In this study, the bonding strength and the corrosion resistance was improved by using thin layer of TiO2. From electrochemical impedance spectroscopy (EIS) study Bod plot, the composite layer of TiO2 and HAp was suggested by the capacitive act as barrier layer coated substrate and prevent the relays of the ion from metallic. The results shows the values of Rox (309.2 k? cm2)are greater than for Rct(19.2 k? cm2), by assumes the presence oxide film increases for coated substrate are greater than that of uncoated, which is a result of the presence of coated film that improve the corrosion resistance of the sample.
In this research, polymer polymethyl methacrylate PMMA composite with nano ceramic Zr and HAp material were used to manufacture one part of the implant system (femoral ball head of hip implant). Three set of hybrid materials were fabricated and tested for this study; the first mixtures which contains 100% (PMMA), the second mixtures which contains (90% (PMMA) + 8% (Zr) + 2% (HAp)), and the third mixtures which contains (80% (PMMA) + 18% (Zr) + 2% (HAp)) were investigated. The mechanical properties for these mixtures increased with the increasing of nano ceramic concentration (Zr and HAp) composite material in the polymer compared to pure polymer PMMA sample. However, an increase in the concentration of Zr from 8% to 18% content cause a considerable decrease of the hardness where a drop of homogeneity in Zr- matrix PMMA contact occurred, V Hardness value are (68 ,80 and 70) Kg.mm for three mixture respectively. The wear test was in agreement with results of the hardness test. The weight loss of the above samples of the wear test were (0.041, 0.035 and 0.037) respectively. According to mechanical properties, the best sample contains (90% (PMMA) + 8% (Zr) + 2% (HAp)). The Scanning electron microscopy resolute showed the particles forming semi-continuous network along grain boundaries polymer for second sample mixtures containing (90% (PMMA) + 8% (Zr) + 2% (HAp)), provides a low atomic packing and high energy. This will make the grain boundaries more reactive and strengthen mechanical performance. The Optical microscopy, Scanning electron microscopy and Xray spectroscopy analysis for In vitro test using SBF shows the growth of HAp layer with an increase in concentration of Ca and P elements formed on the surface of the second sample. This display of good results is a proof of the biocompatibility of the polymer sample.