| Summary: | 碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 105 === Thermal spray technique has been widely used in recent years to prepare hydroxyapatite coating. But the raw materials used in this process are usually micron sized powders and the thickness of the produced coating is very high. In addition, the residual stresses are too high due to inadequate bonding strength between the coating and substrate, and the process is more expensive. To overcome these disadvantages, suspension flame spray technique is introduced in the present study which not only could produce coating of uniform thickness but also have high specific surface area. This study is divided into two parts, the first part is the formation of hydroxyapatite coating by suspension flame spraying on 304 stainless steel to study the phase content, micro-structure and mechanical properties of coating, and the second part study the biocompatibility of hydroxyapatite coating by suspension flame spraying on titanium alloy for different cell morphology and MTT assay. The scanning electron microscopy (SEM) study of coating cross-section showed different morphologies for different parameters used for spraying process. The coating with highest crystallinity (72.8%) and bonding strength (17 MPa) was achieved with working distance of 100 mm and acetylene flow rate of 1.60 Nm3/hr. In vitro test showed that the cell on coating prepared by suspension flame spray had better morphologies than normal flame spray, and also reduced the recovery time.
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