Al基可降解合金的制备及性能研究
发布时间：2018-10-15 18:55
【摘要】：可降解材料因具有制备简单、易加工成形且环境污染小等优点在能源开发和油气开采领域应用广泛,而可降解高分子材料和生物陶瓷由于无法承受高温高压、易变形、降解环境苛刻等缺点不能满足使用要求。相比于可降解高分子和陶瓷材料,可降解金属作为一种新材料,因来源丰富、成本低、适应性强、机械性能和导电导热性良好等优点具有巨大应用空间而深受关注。但目前可降解金属存在结构单一,降解稳定性差等缺点制约其在油气开采领域广泛应用。本论文采用熔铸法在铝中添加合金元素Ga、In和Sn制备综合性能良好的Al基可降解金属材料。本论文采用熔铸法成功制备了用于油气压裂用的可降解Al合金,通过X射线衍射(XRD)、扫描电镜(SEM)及能谱分析(EDS)等测试手段详细研究了Sn、Ga和In等合金元素及热处理工艺对该合金组织和相关性能的影响。并结合电化学极化曲线和腐蚀形貌分析对该Al基合金腐蚀行为及相关机理进行了探讨。以Al-Mg合金为基体,添加元素Sn且随着Sn含量的增加,该合金中出现了Mg2Sn第二相及少量Sn单质,合金基体得到了明显细化,腐蚀电位明显负移,但该合金降解性能较差。在12 wt.% Sn含量基础上,进一步引入3 wt.%的元素Ga时,合金的腐蚀电位进一步负移,在90℃水中具有较高的降解速度,90 min内其质量减少了50%。为了降低该合金的可降解温度,在Al-Mg-Ga-Sn基础上添加不同含量的元素In。电化学测试表明,随着In含量的增加,合金微观组织一定程度细化,其腐蚀电位更负,降解速率不断提高。当In添加量为1.3 wt.%时,在90℃的水中,75 min内质量减少了50%,相比未添加In提高了16.7%；在70℃水中,该合金95 min内质量减少了50%。在此基础上,进一步研究了In和Sn配比对该合金微观组织和性能的影响,随Sn比例提高,合金中Ga-In-Sn共熔体体积逐渐增大,并由颗粒状转变为棒状；但电化学极化曲线表明该合金腐蚀电位正移,活性降低,但当减小Sn的配比时,共熔体体积逐渐减小,腐蚀电位负移,当Ga:In:Sn分别为9：6：4和15：3.5：30时,所制备的Al基合金降解温度得到进一步降低,在50℃水中的分别在440 min和470 min内质量减少了50%。对该合金的热处理结果表明,保温时间相同,热处理温度从300℃升高到500℃时,铝基体晶粒从40～50 μm增长到70～80 μm。同时,第二相含量明显减小,分布更加均匀,极化曲线表明其腐蚀电位略微负移,活性增大；在300℃下延长保温时间,极化曲线表明合金腐蚀电位负移,降解活性增大,在50℃水中反应速率明显大于铸态；在500℃下随保温时间延长,第二相Mg2Sn由棒状变为球形,电化学测试表明合金的腐蚀电位正移,活性降低,原因为球形的合金相与基体接触面积减小。通过极化曲线和腐蚀微观形貌对该Al基可降解合金腐蚀行为分析表明：腐蚀过程中,Mg2Sn合金相作阴极,Al基体作阳极,腐蚀反应从Mg2Sn合金相周围以点蚀开始,点蚀在基体表面扩展导致了合金最后的均匀腐蚀。
[Abstract]:The degradable material has the advantages of simple preparation, easy processing and forming, low environmental pollution and the like, the disadvantages of severe degradation environment and the like can not meet the use requirement. Compared with degradable high polymer and ceramic material, degradable metal as a new material has great application space because of abundant source, low cost, strong adaptability, good mechanical property and good conductive thermal conductivity. However, the existing degradable metal has the disadvantages of single structure, poor degradation stability and the like, and is widely applied in the field of oil and gas exploitation. In this paper, Al-based degradable metal materials with good comprehensive properties are prepared by adding alloy elements Ga, In and Sn in Al. The degradable Al alloy for oil and gas fracturing was successfully prepared by casting method, and Sn was studied by XRD, SEM and EDS. Effect of alloying elements of Ga and In and heat treatment on microstructure and related properties of the alloy. The corrosion behavior and related mechanism of Al-based alloy were discussed in combination with electrochemical corrosion resistance and corrosion morphology analysis. With Al-Mg alloy as matrix, element Sn was added and with the increase of Sn content, the second phase of Mg2Sn and a small amount of Sn simple substance appeared in the alloy, the alloy matrix was obviously refined, and the corrosion potential was obviously negative, but the degradation performance of the alloy was poor. at 12 wt. On the basis of the% Sn content, 3 wt.% was further introduced. When the element Ga is%, the corrosion potential of the alloy is further shifted, the degradation rate is higher in 90 鈩，
本文编号：2273510
[Abstract]:The degradable material has the advantages of simple preparation, easy processing and forming, low environmental pollution and the like, the disadvantages of severe degradation environment and the like can not meet the use requirement. Compared with degradable high polymer and ceramic material, degradable metal as a new material has great application space because of abundant source, low cost, strong adaptability, good mechanical property and good conductive thermal conductivity. However, the existing degradable metal has the disadvantages of single structure, poor degradation stability and the like, and is widely applied in the field of oil and gas exploitation. In this paper, Al-based degradable metal materials with good comprehensive properties are prepared by adding alloy elements Ga, In and Sn in Al. The degradable Al alloy for oil and gas fracturing was successfully prepared by casting method, and Sn was studied by XRD, SEM and EDS. Effect of alloying elements of Ga and In and heat treatment on microstructure and related properties of the alloy. The corrosion behavior and related mechanism of Al-based alloy were discussed in combination with electrochemical corrosion resistance and corrosion morphology analysis. With Al-Mg alloy as matrix, element Sn was added and with the increase of Sn content, the second phase of Mg2Sn and a small amount of Sn simple substance appeared in the alloy, the alloy matrix was obviously refined, and the corrosion potential was obviously negative, but the degradation performance of the alloy was poor. at 12 wt. On the basis of the% Sn content, 3 wt.% was further introduced. When the element Ga is%, the corrosion potential of the alloy is further shifted, the degradation rate is higher in 90 鈩，
本文编号：2273510
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