【摘要】：根據(jù)可降解松質(zhì)骨螺釘?shù)姆郗h(huán)境,及其所處的位置特殊性,為了提高現(xiàn)有的生物醫(yī)用鎂合金材料的耐蝕性以及力學(xué)性能,我們選用了可降解鎂合金來(lái)做骨螺釘。鍶作為人體的必需微量元素,它具有防止動(dòng)脈硬化以及血栓形成的功能,因此本文的實(shí)驗(yàn)內(nèi)容是在本課題組研究的Mg-Zn-Zr合金上設(shè)計(jì)并制備不同Sr含量的Mg-Zn-Zr-Sr合金,并對(duì)其力學(xué)性能、耐腐蝕性以及細(xì)胞毒性進(jìn)行對(duì)比,探究不同含量的Sr元素以及固溶與時(shí)效處理對(duì)鎂合金綜合性能的影響。本研究采用真空與惰性氣體保護(hù)的方法熔煉了Mg-3.2Zn-0.8Zr-0.1Sr、Mg-3.2Zn-0.8Zr-0.3Sr及Mg-3.2Zn-0.8Zr-0.5Sr合金,然后對(duì)其經(jīng)過(guò)300℃×13h均勻化退火,再將鑄錠擠壓成棒材并截取試樣,用光學(xué)顯微鏡觀察試樣的金相組織,并測(cè)量其晶粒尺寸;通過(guò)X射線衍射儀分析Mg-3.2Zn-0.8Zr-0.1Sr、Mg-3.2Zn-0.8Zr-0.3Sr及Mg-3.2Zn-0.8Zr-0.5Sr合金的相組成。為了探究這三種合金的力學(xué)性能,將擠壓好的棒材加工成一些拉伸試樣對(duì)其進(jìn)行拉伸實(shí)驗(yàn);采用三電極法測(cè)量合金的極化曲線;之后再利用固溶處理和時(shí)效處理這兩種熱處理工藝,研究固溶與時(shí)效處理工藝對(duì)合金力學(xué)性能與腐蝕性能的影響;通過(guò)浸泡實(shí)驗(yàn)測(cè)出pH值、Mg離子濃度以及失重來(lái)研究鎂合金在體外的降解速率;最后再通過(guò)細(xì)胞毒性實(shí)驗(yàn)來(lái)檢測(cè)三種合金經(jīng)過(guò)浸泡實(shí)驗(yàn)后,利用浸提液來(lái)檢測(cè)其毒性。結(jié)果表明:1.Mg-3.2Zn-0.8Zr-0.3Sr相比于Mg-3.2Zn-0.8Zr-0.1Sr和Mg-3.2Zn-0.8Zr-0.5Sr合金其力學(xué)性能,耐腐蝕性以及生物相容性最好。2.將三種合金經(jīng)過(guò)固溶處理和時(shí)效處理之后,對(duì)其力學(xué)性能和耐腐蝕性再一次進(jìn)行對(duì)比,得知最適宜的熱處理工藝為在300℃×13h均勻化退火后再進(jìn)行400℃×2h的固溶處理,此時(shí)的力學(xué)性能與耐腐蝕性最好。3.通過(guò)浸泡實(shí)驗(yàn),經(jīng)過(guò)固溶處理的Mg-3.2Zn-0.8Zr-0.3Sr合金的p H值、Mg離子的濃度以及失重相比于擠壓態(tài)的Mg-3.2Zn-0.8Zr-0.3Sr和時(shí)效處理的Mg-3.2Zn-0.8Zr-0.3Sr合金都是最低的,因此經(jīng)過(guò)固溶處理之后的Mg-3.2Zn-0.8Zr-0.3Sr合金的耐腐蝕性最好。4.在細(xì)胞毒性實(shí)驗(yàn)中,Mg-3.2Zn-0.8Zr-0.3Sr合金所產(chǎn)生的細(xì)胞毒性最小。
[Abstract]:According to the service environment of degradable cancellous bone screw and its special position, in order to improve the corrosion resistance and mechanical properties of biomedical magnesium alloy, we chose degradable magnesium alloy as bone screw. Strontium, as a necessary trace element in human body, has the function of preventing arteriosclerosis and thrombosis. Therefore, the experimental content of this paper is to design and prepare Mg-Zn-Zr-Sr alloy with different Sr content on the Mg-Zn-Zr alloy studied by our research group and its mechanical properties. The corrosion resistance and cytotoxicity of magnesium alloys were compared to explore the effects of different contents of Sr and solution and aging treatment on the comprehensive properties of magnesium alloys. In this study, Mg-3.2Zn-0.8Zr-0.1SrPg-3.2Zn-0.8Zr-0.3Sr and Mg-3.2Zn-0.8Zr-0.5Sr alloys were melted by vacuum and inert gas protection. After homogenized annealing at 300 鈩，

本文編號(hào)：2173298