4604

4332

كارشناسي ارشد

شناسايي و انتخاب و روش ساخت مواد

اصفهان: دانشگاه صنعتي اصفهان ، دانشكده مواد

1387

يازده ، 144 ، [II] ص: مصور ، جدول ، نمودار

ص . ع. به: فارسي وانگليسي

محمد حسين فتحي

كيوان رئيسي

88/5/11

احمد منشي ، محمد رضا سائري

1396/09/13

كتابنامه

مهندسي مواد

ID4332

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

AbstractBiological bone is a nanostructured composite that consists of hydroxyapatite HA nanoparticles in a polymeric collagen matrix HA has widely been used as an implantmaterial in clinical applications owing to its desirable properties such as osteoconductivityand bioactivity Its low mechanical properties are not suitable for load bearing cases Oneway to solve this problem is to apply HA coating onto substrates in order to achieve thenecessary mechanical strength and bioactive properties simultaneously HA coating andmetal substrate could not form a chemically bonding interface The addition of ZrO2particles on the HA coating has been got considerable attention because the ZrO2 particlesincrease the bonding strength between HA coating and substrate Sol gel technique can beused to produce nanostructured HA coating and the metallic implant In this studyHA yttria stabilized zirconia YSZ nanopowders and also nanostructured coatings wereprepared by a sol gel method The HA sol was prepared by dissolving C2H5O 3P andCa NO3 2 4H2O in the ethanol absolute under vigorous stirring at room temperature Appropriate amount of Zr OC3H7 4OC3H8 were used as the source of zirconia Theyttrium precursor was obtained by dissolution of 0 3 5 and 8 mol CH3CO2 3Y xH2O in2 propanol alkohol The reinforcements were prepared by 30 wt ZrO2sol X raydiffraction XRD Thermal Gravity Analysis TGA Fourier Transform Infrared FTIR Scanning Electron Microscopy SEM and Transmission Electron Microscopy TEM methods were used to characterize and evaluate of the phase composition thermalbehavior functional groups morphology and particle size of products HA YSZ compositecoatings were performed on 316L stainless steel substrate by the sol gel technique Structural characterization techniques including XRD SEM and EDX were used toinvestigate the microstructure and morphology of the coatings The dissolution rates of thecoatings were measured in a physiological saline solution and the dissolved Ca2 ionconcentration was measured by atomic absorption spectroscopy AAS method It wasfound that at temperatures ranging from 850 to 1050 C the dominant phases of the powderwere HA and tetragonal t zirconia in 3YSZ cubic c zirconia in 8 YSZ and t c Zirconiain 5YSZ phases with the small amounts of tricalcium phosphate TCP and CaZrO3 The crystallinity and the crystallite size of the coating were about 80 and 20 30 nm fortetragonal and cubic zirconia grain size and 60 80 nm for hydroxyapatite grain size respectively Crack free and homogeneous HA YSZ composite coatings were obtainedwith no observable defects The uniform distribution of zirconia particles in compositewould be highly beneficial for obtaining homogeneous coatings of HA YSZ film andwould hinder the grain growth of HA phase during calcinations In vitro evaluation in 0 9 NaCl showed that Ca2 dissolution rate of composite coatings was lower than pure HAcoatings Key WordsHydroxyapatite Zirconia Sol Gel Nanocomposite Yttria Nano particles

محمد حسين فتحي

كيوان رئيسي

احمد منشي ، محمد رضا سائري