本文選題：鎂合金　切入點(diǎn)：微弧氧化　出處：《山東大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：作為潛在的生物醫(yī)用可降解植入體材料,鎂合金具有以下優(yōu)點(diǎn):密度及彈性模量與人體骨組織較為接近,能有效的減少應(yīng)力遮蔽效應(yīng),適用于骨組織修復(fù)及替代,從而促進(jìn)骨組織生長(zhǎng);骨骼系統(tǒng)中的鎂有利于骨生長(zhǎng)及骨強(qiáng)度的提高,其溶解過(guò)程不產(chǎn)生任何副作用。然而,鎂在人體內(nèi)的降解速度過(guò)快,無(wú)法在新骨組織長(zhǎng)成之前完成支撐任務(wù)。降解產(chǎn)生的氫氣聚集在植入體周圍,阻礙了傷口愈合,同時(shí)也提高了植入體周圍組織的pH值,甚至發(fā)生堿中毒。鎂的提純,合金化及表面改性可以作為增強(qiáng)耐蝕性的三種不同解決方法。本實(shí)驗(yàn)采用鍶元素合金化制備性能優(yōu)良的Mg-2Sr合金,隨后制備微弧氧化膜層,實(shí)現(xiàn)合金化和表面改性的結(jié)合。本文的研究?jī)?nèi)容為不同電解液體系下Mg-2Sr合金表面微弧氧化膜層的制備與生物相容性研究。具體的,首先自行澆鑄Mg-2Sr合金基體;其次對(duì)比了不同聚乙二醇含量的膜層的性能,并給出最佳添加量數(shù)值;隨后研究了有機(jī)鈣源(葡萄糖酸鈣,乳酸鈣)和無(wú)機(jī)鈣源(碳酸鈣,氫氧化鈣)對(duì)微弧氧化膜層的組織結(jié)構(gòu),電化學(xué)行為和體外降解行為的影響;最后選擇優(yōu)化的鈣源乳酸鈣和碳酸鈣,研究了鈣磷摩爾比對(duì)微弧氧化膜層組織結(jié)構(gòu)與生物活性的影響。結(jié)果表明,Mg-2Sr合金中的一部分鍶元素和鎂結(jié)合生成中間化合物,另一部分鍶元素則以固溶體的形式存在于合金中,合金的實(shí)際成分為Mg-2.24Sr。聚乙二醇的加入使得微弧氧化膜層的厚度略有降低且差別不大,含有8g/L的PEG1000電解液體系制備的膜層具有最大的結(jié)合力,為15.75N,且具有最強(qiáng)的耐蝕性及最低的降解速率,浸泡前2天內(nèi),試樣出現(xiàn)了增重的現(xiàn)象。以有機(jī)鈣源和無(wú)機(jī)鈣源制備的微弧氧化膜層浸泡后出現(xiàn)了 Ca_2P_2O_7(CCP),Mg(OH)_2,HA 和 Ca_(10-x)Sr_x(PO_4)_6(OH)_2(Sr-HA)等新的物相,Ca_(10-x)Sr_x(PO_4)_6(OH)_2相是元素Sr取代了羥基磷灰石中元素Ca的位置而形成的一種新的生物相容性磷灰石,該相可以促進(jìn)骨植入體周圍細(xì)胞的生長(zhǎng)、繁殖和修復(fù)。以乳酸鈣為鈣源制備的膜層在SBF浸泡后的表面顆粒狀腐蝕產(chǎn)物中鈣磷相含量較高。以碳酸鈣為鈣源,鈣磷比為1:4和1:5的膜層的腐蝕產(chǎn)物中出現(xiàn)了沿腐蝕裂紋分布納米棒和納米線狀的物質(zhì),兩種鈣源下鈣磷比為1:4的膜層在SBF中浸泡21天后的失重率僅有13%,這利于保證植入體在體內(nèi)環(huán)境的力學(xué)穩(wěn)定性。
[Abstract]:As a potential biomedical biodegradable implant, magnesium alloy has the following advantages: density and modulus of elasticity are close to human bone tissue, can effectively reduce stress shielding effect, and can be used for bone tissue repair and replacement. Magnesium in the bone system is beneficial to bone growth and bone strength, and does not cause any side effects. However, magnesium degrades too quickly in the human body. The hydrogen generated by the degradation accumulates around the implant, hinders wound healing, increases the pH value of the tissue around the implant, and even causes alkalosis. Alloying and surface modification can be used as three different solutions to enhance corrosion resistance. In this experiment, Mg-2Sr alloys with excellent properties were prepared by strontium alloying, and then micro-arc oxide films were prepared. In this paper, the preparation and biocompatibility of micro-arc oxide film on Mg-2Sr alloy surface under different electrolyte systems were studied. Firstly, the substrate of Mg-2Sr alloy was cast by itself. Secondly, the properties of the film with different polyethylene glycol content were compared, and the optimum addition value was given. Then, the organic calcium sources (calcium gluconate, calcium lactate) and inorganic calcium sources (calcium carbonate) were studied. The effect of calcium hydroxide on the structure, electrochemical behavior and degradation behavior of the micro-arc oxide film. Finally, the optimized calcium sources calcium lactate and calcium carbonate were selected. The effects of Ca / P molar ratio on the microstructure and bioactivity of the microarc oxide film were studied. The results showed that some strontium elements in Mg-2Sr alloy combined with magnesium to form intermediate compounds, and the other strontium elements existed in the alloy as solid solution. The actual composition of the alloy is Mg-2.24Sr.The addition of polyethylene glycol makes the thickness of the micro-arc oxide film slightly lower and the difference is not obvious. The PEG1000 electrolyte system containing 8g / L has the greatest adhesion. Is 15.75Nand has the strongest corrosion resistance and the lowest degradation rate, within 2 days before soaking, After soaking in the micro-arc oxide film prepared by organic and inorganic calcium sources, Ca2P2O7C / C / C _ 2O _ 7 / C / C / C _ 2O _ 7 / C _ 2O _ 7 / C _ 2O _ 7 / C _ 2O _ 7 / C _ 2O _ 7 / C _ 2O _ 7 / C _ 2O _ 7 / C _ 2O _ 7 / C _ 2O _ 7 / C _ 2C _ 2O _ 7 / C _ 2C _ 2C _ 2C _ H _ 2C _ H _ 2H _ H _ 2H _ H _ 2H _ H _ 2, etc., new phases such as Ca10 ~ (-x) -x ~ (-) Sr _ (x) O _ (4) O _ (4) O _ (6) O _ (-HAH), etc. A new biocompatible apatite, This phase can promote the growth, reproduction and repair of the cells around the bone implants. The calcium phosphate phase in the coating prepared by calcium lactate as calcium source is higher in the surface granular corrosion products after immersion in SBF, and calcium carbonate is used as calcium source. Nanorods and nanowires distributed along corrosion cracks were found in corrosion products of films with Ca / P ratios of 1: 4 and 1: 5. The weight loss rate of the film with Ca / P ratio of 1: 4 to 1: 4 immersed in SBF for 21 days was only 13% under two calcium sources, which was helpful to ensure the mechanical stability of the implant in vivo.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TG174.4

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相關(guān)期刊論文 前2條

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本文編號(hào)：1626801