本文關(guān)鍵詞： 血管支架 CoCrMo合金 Ti-O薄膜 疲勞性 耐腐蝕性　出處：《西南交通大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：鈷合金因其高強(qiáng)度、抗疲勞等特性成為制備細(xì)金屬絲冠脈支架的主選材料。然而無論是其裸支架,還是藥物洗脫性支架都存在再狹窄或晚期血栓的風(fēng)險,究其原因在于金屬基體的抗凝血性能不足。前期研究表明,Ti-O薄膜具有良好的血液相溶性,利用Ti-O薄膜對血管支架進(jìn)行表面改性,有望解決這一難題。本文主要針對血管支架在人體內(nèi)的服役情況,開展鈷合金表面Ti-O薄膜的制備以及Ti-O薄膜/CoCrMo體系的彎曲疲勞行為與耐腐蝕行為的研究工作。 Ti-O薄膜的制備采用高功率磁控濺射法(HPPMS),并采用X射線衍射法(XRD)、 X射線光電子能譜法(XPS)對薄膜相結(jié)構(gòu)和成分進(jìn)行了表征。Ti-O薄膜/CoCrMo體系彎曲疲勞行為的評價采用本文獨自發(fā)展的一種實驗方法,利用該方法本文主要研究了薄膜厚度、應(yīng)力幅大小、表面形貌對Ti-O薄膜/CoCrMo體系彎曲疲勞行為的影響。采用電化學(xué)極化實驗研究了經(jīng)數(shù)百萬次至千萬次循環(huán)加載荷后Ti-O薄膜/CoCrMo體系耐腐蝕性能。全文主要內(nèi)容和結(jié)論如下： (1)利用HPPMS方法在CoCrMo合金表面成功制備出金紅石型Ti02薄膜； (2)基于懸臂梁共振和純彎曲理論本文獨自發(fā)展出一種評價薄膜彎曲疲勞壽命的實驗方法； (3)疲勞實驗表明,應(yīng)力幅200Mpa下,循環(huán)加載荷1000萬次后,Ti-O薄膜表面未見裂紋和預(yù)制裂紋的擴(kuò)展,本文制備的Ti-O薄膜能夠滿足支架服役過程中不失效：表面質(zhì)量是影響薄膜疲勞失效的一個重要因素,表面光滑致密的薄膜抗疲勞失效的能力越強(qiáng)；薄膜厚度對彎曲疲勞行為影響不顯著； (4)電化學(xué)實驗表明,經(jīng)數(shù)百萬至千萬次循環(huán)加載后的薄膜試樣,其耐腐蝕行能相對于未加載試樣有所降低,但仍然高于裸金屬樣品；膜厚大的樣品耐蝕性能優(yōu)于膜厚小的試樣；表面光滑致密的薄膜耐蝕性優(yōu)于表面粗糙、疏松的薄膜。 本文的研究結(jié)果,為Ti-O薄膜表面改性鈷基合金血管支架及其應(yīng)用提供一定的理論依據(jù)。
[Abstract]:Cobalt alloy has become the main material for the preparation of thin wire coronary stent due to its high strength and anti-fatigue properties. However, both bare stent and drug-eluting stent are at risk of restenosis or late thrombosis. The reason lies in the lack of anticoagulant properties of metal substrates. Previous studies showed that Ti-O thin films have good blood compatibility. The surface modification of vascular scaffolds was carried out by using Ti-O film. It is expected to solve this problem. This paper focuses on the service of vascular stent in human body. The preparation of Ti-O film on cobalt alloy surface and the bending fatigue behavior and corrosion resistance of Ti-O film / CoCrMo system were studied. The Ti-O thin films were prepared by high power magnetron sputtering (HPPMS) and X-ray diffraction (XRD). The phase structure and composition of Ti-O films were characterized by X-ray photoelectron spectroscopy (XPS). The bending fatigue behavior of Ti-O films / CoCrMo system was evaluated by an experimental method developed in this paper. In this paper, the thickness and stress amplitude of the film are studied by using this method. Effect of surface morphology on bending fatigue behavior of Ti-O films / CoCrMo system. Electrochemical polarization experiment was used to study the bending fatigue behavior of Ti-O / CoCrMo films after millions to tens of millions of cycles and loading. Corrosion resistance of the system. The main contents and conclusions are as follows:. 1) rutile Ti02 thin films were successfully prepared on the surface of CoCrMo alloys by HPPMS method. Based on the theory of cantilever beam resonance and pure bending, an experimental method for evaluating the bending fatigue life of thin films has been developed in this paper. 3) fatigue tests show that there are no cracks and prefabricated cracks on the surface of Ti-O films after 10 million cycles of cyclic loading at 200Mpa stress amplitude. The Ti-O films prepared in this paper can meet the requirements of the scaffold service without losing efficiency: the surface quality is an important factor affecting the fatigue failure of the thin films, and the stronger the anti-fatigue failure ability of the thin films with smooth and compact surface is; The effect of film thickness on bending fatigue behavior is not significant. (4) Electrochemical experiments show that the corrosion resistance of thin film specimens after millions to ten million cycles is lower than that of unloaded samples, but still higher than that of bare metal samples. The corrosion resistance of the sample with large film thickness is better than that of the sample with small film thickness. The corrosion resistance of thin film with smooth and compact surface is better than that with rough surface and loose surface. The results of this paper provide a theoretical basis for the surface modification of cobalt-based alloy stent and its application in Ti-O film.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：O484.1

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本文編號：1467748