Cu对Mg-6Al-1Zn-1.0Sn可溶镁合金组织和性能的影响  

Effects of Cu on the microstructure and properties ofMg-6Al-1Zn-1.0Sn dissolvable magnesium alloy

作　　者：马巍 陈百华[1] 马正青[2] 汪海 MA Wei;CHEN Baihua;MA Zhengqing;WANG Hai(The Second Xiangya Hospital,Central South University,Changsha 410011,China;Material science and Engineering college,Central South University,Changsha 410012,China)

机构地区：[1]中南大学湘雅二医院,长沙410011 [2]中南大学材料科学与工程学院,长沙410083

出　　处：《功能材料》2024年第9期9157-9163,共7页Journal of Functional Materials

基　　金：湖南省自然科学基金项目(2021JJ30925)。

摘　　要：可溶镁合金作为油气田增效开采中的桥塞和压裂球材料,需兼具良好的强度、塑性和较快的溶解速度,目前应用的可溶镁合金存在力学性能和溶解性能较差等不足。以Mg-6Al-1Zn-1.0Sn合金为基体,添加不同含量的Cu元素,通过铸造、挤压法制备了Mg-6Al-1Zn-1.0Sn-x Cu(x=0.5,1.5和2.5)合金。采用扫描电镜(SEM)、X射线衍射仪(XRD)、金相显微镜(OM)观察了Mg-6Al-1Zn-1.0Sn-x Cu(x=0.5,1.5和2.5)合金的显微组织和形貌;利用塔菲尔曲线、腐蚀失重、室温拉伸等检测技术,研究了添加元素Cu对Mg-6Al-1Zn-1.0Sn-x Cu(x=0.5,1.5和2.5)镁合金的溶解速度和力学性能的影响。结果表明,Cu元素的添加,形成了AlCuMg相,提高了合金凝固时的形核率,晶粒细化,改善了Mg-6Al-1Zn-1.0Sn-x Cu(x=0.5,1.5和2.5)溶解均匀性;随铜含量增加、固溶处理温度升高,Mg-6Al-1Zn-1.0Sn-x Cu(x=0.5,1.5和2.5)镁合金溶解速度增大、强度降低、延伸率增大。固溶温度为425℃+2 h、时效温度为180℃+24 h的Mg-6Al-1Zn-1.0Sn-0.5Cu合金抗拉强度为290 MPa,屈服强度为194 MPa,延伸率为14.0%,在60,90℃的3.5%(质量分数)KCl溶液中的溶解失重速度分别为28.65,32.52 mg/(h·cm^(2))。本研究为开发岩气开采可溶性镁合金材料提供了理论参考。Dissolvable magnesium alloys,employed as bridge plugs and fracturing balls in enhanced oil and gas field extraction,must exhibit excellent strength,plasticity,and rapid dissolution rates.However,the currently used dissolvable magnesium alloys are often limited by their inadequate mechanical and dissolution properties.In this study,Mg-6Al-1Zn-1.0Sn alloy was used as a base material,with varying Cu content(x=0.5,1.5,and 2.5)added.The Mg-6Al-1Zn-1.0Sn-x Cu(x=0.5,1.5,and 2.5)alloys were prepared through casting and extrusion methods.Microstructure and morphology of the alloys were characterized using scanning electron microscopy(SEM),X-ray diffraction(XRD),and optical microscopy(OM).The effects of Cu addition on the dissolution rate and mechanical properties of Mg-6Al-1Zn-1.0Sn-x Cu(x=0.5,1.5,and 2.5)alloys were investigated using Tafel curves,weight loss measurements,and room temperature tensile tests.The results indicate that the addition of Cu forms AlCuMg phases,which enhance the nucleation rate during solidification,refine the grains,and improve the dissolution uniformity of Mg-6Al-1Zn-1.0Sn-x Cu(x=0.5,1.5,and 2.5)alloys.With increasing Cu content and solution treatment temperature,the dissolution rate of Mg-6Al-1Zn-1.0Sn-x Cu(x=0.5,1.5,and 2.5)alloys increases while the tensile strength decreases,and the elongation improves.The Mg-6Al-1Zn-1.0Sn-0.5Cu alloy,subjected to a solution treatment at 425℃for 2 hours and aging at 180℃for 24 hours,exhibited a tensile strength of 290 MPa,a yield strength of 194 MPa,and an elongation of 14.0%.The dissolution rates in 3.5 wt%KCl solution at 60℃and 90℃were 28.65 mg/(h·cm^(2))and 32.52 mg/(h·cm^(2)),respectively.This study provides a theoretical reference for the development of dissolvable magnesium alloy materials for shale gas extraction.

关 键 词：镁合金 铜 机械性能 微观组织 溶解速度 

分 类 号：TG146[一般工业技术—材料科学与工程]