| Summary: | 碩士 === 國立屏東科技大學 === 材料工程研究所 === 106 === In this study, after the biomedical pure-grade titanium (GR.4) metal test specimen was subjected to anodizing, Type II anodizing and micro-arc oxidation, the surface morphology, material analysis, crystalline phase analysis, roughness, wettability analysis, surface hardness test, surface wearability test, surface corrosion test are conducted to the test specimen in order to evaluate its surface properties.
The results show that, after biomedical pure-grade titanium (GR.4) was subjected to anodizing, Type II anodizing and micro-arc oxidation, TiO2 oxide film forms on the surface which is rich in oxygen and phosphorus. It was addressed with Type II anodizing, and the thickness of oxide film was influenced by voltage and oxidation time; also, bubbles traces of pushing are likely formed on the surface. It possesses TiO2 (Anatase) with crystalline phase, and thus the surface roughness was increased from 50.3nm and 51.3nm to 73.0nm; the hardness was also increased from 263.7 HV and 282 HV to a maximum of 346.86 HV due to thicker oxide film. The increase of hardness and roughness can affect the wearability of the test specimen’s surface. The scratch depth decreases from 5.2μm and 4.5μm to a minimum of 0.5μm. The surface is rich in oxygen and phosphorus, which results in the decrease of contact angle value from 60.53° and 58.99° to a minimum of 40.39°. The surface electric corrosion potential (Ecorr) increased from -0.2 Ewe/V and -0.23Ewe/V to 0.1 Ewe/V due to oxide film after anodizing of biomedical pure-grade titanium (GR.4); thus, it is more resistant to corrosion. The thickness of the oxide film increases due to voltage and oxidation time after the micro-arc oxidation, and the surface has micro-pores and TiO2 (Anatase) crystalline phase, which increases the surface roughness from 50.3nm and 51.3nm to 111.2 nm, and the hardness increases from 263.7 HV and 282 HV to a maximum of 372.64 HV due to thicker oxide film. The increase of hardness and roughness can affect the wearability of the test specimen’s surface. The scratch depth decreases from 4 μm and 3 μm to a minimum of 0.2μm. The surface is rich in oxygen and phosphorus, which results in the decrease of contact angle value from 60.53° and 58.99° to a minimum of 35.89°. The electric corrosion potential (Ecorr) is increased by -0.2 Ewe/V and -0.23Ewe/V to -0.06 Ewe/V due to oxide film after anodizing of biomedical pure-grade titanium (GR.4); thus, it is more resistant to corrosion. In sum, the surface analysis results show that the performance after both addressing is better than non-addressed biomedical pure-grade titanium (GR.4) and anodizing. It is expected that the two addressing have good mechanical properties.
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