Ca含量对AZ61-1.2Y镁合金耐蚀性能的影响

利用静态失重法研究了不同Ca含量对AZ61-1.2Y镁合金腐蚀速率的影响。用金相显微镜、扫描电子显微镜观察试样的微观组织、表面腐蚀形貌。结果表明,添加1%的Ca(质量分数,下同)时,合金的晶粒得到了明显的细化,组织和成分更加均匀;当Ca含量大于1%时,合金的析出相增多,并产生粗化、偏聚的现象。在两种浓度的腐蚀介质中（0.5%和3.5%的NaCl水溶液）,合金的腐蚀速率均随着Ca含量的增加呈现先减小后增大的趋势,其中当Ca含量为1%时合金的腐蚀速率均达到最低,耐蚀性能得到明显的改善。     

铸态Mg-xSn-1Mn合金的显微组织和阻尼性能

采用光学显微镜(OM)、维氏硬度计、热动态分析仪、X射线衍射(XRD)、多功能内耗仪等,研究了Sn含量对Mg-xSn-1Mn合金显微组织、阻尼性能和力学性能的影响。结果表明:当Sn含量从2%增加到8%时,Mg-xSn-1Mn合金的枝晶间隙呈现细化的趋势,硬度从43.84 HV0.1增加至54.00 HV0.1,呈单调增加的趋势。应变无关阻尼随着Sn含量的增加呈现先增后减的趋势,在Sn含量为4%时达到最大,应变相关阻尼则随着Sn含量的增加呈现逐渐减小的趋势。在低温阶段,相同Sn含量的合金的阻尼随着频率的增大呈现增加的趋势;但在高温下,阻尼值在低频时的上升速率比高频时快,并随着温度的升高,低频阻尼和高频阻尼趋向于相等。当Sn含量不同时,随着温度的升高,Sn含量较高的合金的阻尼值上升速率变快。     

Sn对Mg-6Al合金腐蚀行为的影响

采用常温浸泡方法和质量损失法研究了加入不同含量(0.5～2.0 mass%)的Sn对Mg-6 mass%Al合金在0.5 mass%NaCl溶液中腐蚀行为的影响,采用扫描电镜观察了合金的腐蚀形貌,采用光学显微镜对合金的显微组织进行了观察。结果表明:合金的腐蚀形貌与腐蚀速率测试结果具有较强的一致性;不含Sn时,Mg-6Al合金的腐蚀速率为0.985 mm/a,随着Sn含量从0.5%增加到2.0%,Mg-6Al合金的腐蚀速率先降低后升高;当Sn含量为1.0%时,Mg-6Al合金的腐蚀速率达到最低,为0.568 mm/a,此时合金的耐腐蚀性能最好,这主要是由于向Mg-6Al合金中加入适量的Sn后,可细化合金的显微组织,同时降低腐蚀速率,并且改善腐蚀形貌,进而显著提高合金的耐腐蚀性能。     

Sn对Mg-Nd-Zn-Zr合金组织和耐蚀性能的影响

通过金相显微镜、扫描电镜、X射线衍射仪等设备分析了Sn对铸态Mg-2.7Nd-0.4Zn-0.5Zr合金显微组织和腐蚀性能的影响。结果表明,铸态Mg-2.7Nd-0.4Zn-0.5Zr-xSn(x=0.5、1.0、1.5、2.0)合金的组织是由α-Mg基体、Mg_(12)Nd相、点状或杆状的Mg_2Sn相组成。随着Sn含量的增加,Mg_2Sn相逐渐增多。铸态合金的腐蚀速率随着Sn含量的增加呈现先减小后增大的趋势,其中当Sn含量为1.0%时合金具有最佳的耐腐蚀性能。Sn的加入能够细化Mg_(12)Nd相,同时析出更稳定性的Mg_2Sn相,并在Sn含量为1.0%时分布较为均匀。     

Zr-XSn-1Nb-0.3Fe(X=0~1.5)合金的腐蚀行为研究

通过高压釜腐蚀实验研究了Zr-XSn-1Nb-0.3Fe合金(X=0~1.5,质量分数,%)在360℃/18.6 MPa纯水、360℃/18.6 MPa/0.01 mol·L-1 LiOH水溶液以及400℃/10.3 MPa过热蒸汽中的耐腐蚀性能。结果表明,随着Sn含量从1.5%降低至0.6%,合金试样腐蚀增重降低;进一步降低Sn含量时,合金在纯水和蒸汽中的腐蚀增重没有明显变化,但在LiOH水溶液中的腐蚀增重反而增加。采用透射电镜表征腐蚀前的显微组织发现,随着Sn含量的变化,合金中第二相的大小及类型相接近,但面密度随着Sn含量的增加而减少。采用激光拉曼光谱分析腐蚀过程中氧化膜晶体结构表明,腐蚀初期氧化膜的结构以m-ZrO2和t-ZrO2为主,随着腐蚀时间的增加,t-ZrO2转变为m-ZrO2;t-ZrO2转变越快,t-ZrO2含量越低,腐蚀速率越高。     

添加锡对AS21镁合金显微组织和耐腐蚀性能的影响（英文）

研究添加锡对AS21镁合金显微组织和耐腐蚀性能的影响。采用低压压铸法制备分别添加0、0.5、1和2 wt.%Sn的AS21合金。用光学显微镜和扫描电镜进行显微组织表征,通过在3.5%Na Cl溶液中浸渍和电化学腐蚀试验研究合金的耐腐蚀性能。微观检测结果显示,AS21合金中含有α-Mg、孤立的β-Mg_(17)Al_(12)和汉字状Mg_2Si金属间化合物相。随着Sn含量的增加,Mg_2Si相的分布变得更加离散和致密。当Sn添加量为2 wt.%时,形成遍布于整个组织的富Sn网状结构,汉字状组织由短棒状的Mg_2Si相排列组成。持续浸泡腐蚀试验表明,随着锡含量的增加,AS21合金的降解程度不断降低,当锡含量为2wt.%时,AS21合金的腐蚀速率降低约65%。电化学腐蚀试验也表明,随着锡含量的增加,AS21合金的耐蚀性逐渐提高。     

镁合金运动器材的耐腐蚀性能研究

采用失重法、集气法、极化曲线法研究了Sr含量对体育器械用Mg-6Al合金耐腐蚀性能的影响。结果表明,随着Sr含量的增加,合金的腐蚀速率呈增加趋势,但当Sr含量为1%时,合金的腐蚀速率降低。合金耐腐蚀性能提高的主要原因在于晶界处析出Al4Sr相可以有效地抑制腐蚀的扩散。此外,Sr的加入可以促使晶粒细化,使腐蚀均匀性得到提高。     

Sn对Zn4Al3Cu无铅钎料腐蚀性能的影响

根据合金化原理,在Zn4Al3Cu钎料基体上添加不同含量Sn,形成一种新型合金,研究了Sn含量对Zn4Al3CuxSn钎料合金腐蚀性能的影响。结果表明:随着Sn含量增加,Zn4Al3CuxSn钎料合金的腐蚀速率逐渐升高。其中,Zn4Al3Cu钎料的腐蚀速率最低,为0.076 mm/a,耐蚀性最好。随着Sn添加量增加,Zn4Al3CuxSn钎料合金的腐蚀电位逐渐降低,w(Sn)为15%时,钎料腐蚀电位最低,为-1.201 1 V,较基体钎料Zn4Al3Cu腐蚀电位降低了0.063 V。     

Fe含量对CuNi10FeMn1合金组织与性能的影响

研究Fe含量(1.05%~2.44%,质量分数)对CuNi10FeMn1合金组织、微观偏析、耐海水冲刷腐蚀性能和力学性能的影响,采用SEM、能谱和XPS等手段分析合金的腐蚀产物膜。结果表明:CuNi10FeMn1合金中Ni、Fe元素易于富集在枝晶干,Mn元素易于富集在枝晶间;随着Fe含量的增加,合金组织明显细化,α固溶体中的Fe含量增加;当Fe含量从1.05%增大至1.80%时,Ni、Fe元素的偏析比分别由0.49和0.45增大到0.77和0.61,偏析程度下降;当Fe含量继续增大时,Ni、Fe元素的偏析比则下降为0.62~0.65和0.49~0.51,偏析程度也随之增加。随着Fe含量的增加,合金的腐蚀速率呈先减小后增大的趋势,当Fe含量为1.80%时,合金腐蚀速率最小,表面形成致密的、缺陷较少的富Fe、Ni的腐蚀产物膜,对基体的保护作用增强,是其具有良好耐海水冲刷腐蚀性能的主要原因。随着Fe含量的增加,CuNi10FeMn1合金的抗拉强度和屈服强度由Fe含量为1.05%时的245和90MPa分别增大到Fe含量为2.44%时的303和151MPa,而断后伸长率由39.2%下降到32.8%。     

铸态Mg-Sn-Zn-Al合金组织性能

研究含Sn5%,8%,11%及Zn0.5%,1%,2%的Mg-xSn-yZn-1.0Al合金(质量分数)的显微组织演变和力学性能变化,在此基础上优化合金的成分比,得出在Sn:Zn=5:1和Sn:Zn=6:2.5时有较佳的综合力学性能。显微组织观察表明,Zn元素能够起到明显的晶粒细化作用,显著提高合金的抗拉强度,但过量的Zn会使合金的伸长率显著下降。Sn含量的增加可以明显地改善合金的树枝晶组织,并使其等轴化,但Sn含量的增加使合金的抗拉强度明显下降。同时增加Sn和Zn元素的含量时,Sn含量的变化成为合金组织演变的主要原因;减少Sn和Zn元素的含量时,Zn含量的变化成为合金组织演变的主要原因。     

Sn对Mg-6Al-1.2Y-0.9Nd镁合金组织和性能的影响

采用XRD、OM、SEM和EDS等手段研究Sn对Mg-6Al-1.2Y-0.9Nd合金微观组织和力学性能的影响。结果表明, Sn可以显著提高合金从室温到175 ℃区间的抗拉强度,当Sn含量为1%时,镁合金在室温和175 ℃时抗拉强度达到最大值,分别为242和192 MPa,合全的拉伸断口为具有塑性特征的准解理断裂。 Sn的加入使合金的显微组织得到明显细化,并出现高熔点Mg2Sn合金相。合金力学性能的提高主要是由于细晶强化、弥散强化和固溶强化。     

Effects of Sb,Sm, and Sn additions on the microstructure and mechanical properties of Mg-6Al-1.2Y-0.9Nd alloy

The microstructure and mechanical properties of Mg-6Al-1.2Y-0.9Nd magnesium alloy with Sb, Sm, or Sn addition were investigated through X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The results show that small amounts of Sb, Sm, and especially Sn can refine the grains of the alloy. High melting point Sb₃Y₅, Al₂Sm, and Nd₅Sn₃ intermetallic compounds can be formed respectively when Sb, Sm, and Sn are added to the alloy. Sb and Sm can improve the tensile strength of the alloy at ambient and elevated temperatures. The tensile strength of the alloy with Sm addition is the highest at 293 and 423 K. However, the tensile strength of the alloy with Sn addition is the highest at 448 K.     

Effect of rare-earth element Sm on the corrosion behavior of Mg-6Al-1.2Y-0.9Nd alloy

The effect of Sm (0 wt.%-2 wt.%) addition on the corrosion behavior of Mg-6Al-1.2Y-0.9Nd alloy in 3.5 wt.% NaCl solution has been studied by static corrosion tests, corrosion morphology observation, corrosion scale and microstructure analysis. The results show that, with the increasing of Sm content, the corrosion rate of the alloy decreases at first, then increases and reaches the valley at 0.5 wt.% Sm. The reason is that the proper content of Sm addition can refine the precipitates and make the component and microstructure uniform, and therefore, it remarkably improves the corrosion resistance of the alloy.     

Sm对Mg-6Al-1.2Y-0.9Nd合金组织和性能的影响

采用XRD、OM、SEM和EDS等手段研究Sm对Mg-6Al-1.2Y-0.9Nd合金微观组织和力学性能的影响。结果表明,合金中加入Sm后,Sm优先与A1形成高熔点Al2Sm弥散颗粒质点,当Sm含量(1.5%～2.0%)较高时,合金内出现针状Mg12Nd相。在研究范围内,随Sm含量的增加,合金的常温和高温力学性能略有升高然后降低;而合金的延伸率呈现不断降低的趋势。合金的拉伸断口为具有塑性特征的准解理断裂。     

复合添加Y和Nd对Mg-Li合金显微组织及室温压缩织构的影响

采用OM,SEM,XRD,EBSD及电子万能试验机,对比研究了Mg-5Li-3Al-2Zn和Mg-5Li-3Al-2Zn-1.2Y-0.8Nd铸态合金的显微组织、力学性能以及室温单向压缩后的织构演变.研究发现,复合添加Y和Nd 2种稀土元素后,合金中絮丝状AlLi相明显减少,晶粒得到显著细化,平均尺寸在30μm左右.2种合金的塑性表现良好,加入少量稀土的合金室温压缩的变形量可达到27%.复合添加的稀士元素大幅度降低了Mg品格的c/a值,显著弱化了合金的基面织构,激活了锥面滑移系的同时,也使得室温下少见的柱面滑移破激活.     

Fluidity,Microstructure, and Tensile Properties of Sub-rapidly Solidified Mg-6Al-4Zn-xSn(x=0,0.6,1.2,1.8) Alloy

In this paper, the infl uence of the Sn element on the melt viscosity, grain size, shrinkage, and tensile properties of the subrapidly solidified Mg-6Al-4Zn alloy was studied. The results showed that the melt viscosity of the Mg-6Al-4Zn alloy was greatly decreased because of the addition of Sn. As the content of Sn increased from 0 to 1.8 wt.%, the grain size of the alloy was refined, and the dendrite microstructure was changed to rose-shaped ones simultaneously. The decreased melt viscosity and refined microstructure were conductive to the feeding of melt, which contributed to the reduction in volume fraction of shrinkage. The volume fraction of shrinkage of the Mg-6Al-4Zn-1.2 Sn alloy was reduced by 30.8%, compared with that of the alloy without Sn addition. Tensile properties of the Mg-6Al-4Zn-x Sn alloys were increased firstly and then decreased with the augmented Sn content. The yield strength, ultimate tensile strength, and elongation of the alloy containing 1.2 wt.% Sn were 21.4%, 39.5%, and 259.0% higher than those of the alloy without Sn addition, respectively. The addition of Sn was considered to reduce the shrinkage of the sub-rapidly solidified Mg-6Al-4Zn magnesium alloy and thus improved its tensile properties. To identify the mechanism, the effect of Sn on the volume fraction of shrinkage was discussed from three aspects of melt viscosity, grain refinement, and volume fraction of eutectic phases.     

Effects of minor Ca on as-cast microstructures and mechanical properties of Mg-3Ce-1.2Mn-0.9Sc and Mg-4Y-1.2Mn-0.9Sc alloys

The effects of the addition of 0.6% Ca (mass fraction) on the as-cast microstructure and mechanical properties of the Mg-3Ce-1.2Mn-0.9Sc and Mg-4Y-1.2Mn-0.9Sc magnesium alloys were investigated and compared by optical microscopy and scanning electron microscopy, differential scanning calorimetry analysis, and tensile and creep tests. The results indicate that the addition of 0.6% Ca to the Mg-3Ce-1.2Mn-0.9Sc and Mg-4Y-1.2Mn-0.9Sc alloys can refine the grains of the two alloys. At the same time, the addition of 0.6% Ca to the Mg-3Ce-1.2Mn-0.9Sc and Mg-4Y-1.2Mn-0.9Sc alloys can effectively improve the tensile properties of the two alloys. In addition, the addition of 0.6% Ca can also improve the creep properties of the Mg-3Ce-1.2Mn-0.9Sc alloy but is not beneficial to the creep properties of the Mg-4Y-1.2Mn-0.9Sc alloy. The different effects of minor Ca on the creep properties of the Mg-3Ce-1.2Mn-0.9Sc and Mg-4Y-1.2Mn-0.9Sc alloys are possibly related to the difference in the solid solubilities of Ce and Y in Mg.     

Ce对Mg-9Gd-4Y-1Nd-0.6Zr合金微观组织和耐蚀性的影响

为获得高强耐蚀的镁稀土合金,采用扫描电镜、X射线衍射分析、腐蚀失重法、电化学阻抗和动电位极化等研究了元素Ce对Mg-9Gd-4Y-1Nd-0.6Zr合金微观组织和耐蚀性的影响。结果表明添加0.5% Ce后合金耐腐蚀性能较好,合金的腐蚀电流密度为不含铈合金的55.6%,腐蚀电位正移约141 mV。适量Ce元素的加入导致其他稀土元素在晶界处富集并呈网状分布,使第二相粒子尺寸变小,体积分数变大。     

Mg-Al-Nd/Sr耐热镁合金的组织结构与蠕变性能

以Mg-6Al合金为基体,分别单一添加稀土Nd、Sr和复合添加稀土Nd和碱土Sr元素,采用水冷模工艺制备Mg-6Al-6Nd,Mg-6Al-2Sr和Mg-6Al-2Sr-2Nd耐热镁合金,并比较研究单一添加Nd或Sr和复合添加稀土Nd和碱土Sr对合金组织结构和蠕变性能的影响。结果表明:复合添加稀土Nd和碱土Sr后,合金中除了析出第二相Al2Nd、Al11Nd3和Al4Sr外,还析出Sr和Nd相互取代的Al4(Sr,Nd)和Al11(Nd,Sr)3复合相;在Mg-6Al-2Sr基础上添加2%Nd,不仅细化合金枝晶间距,还显著地提高第二相的分布密度,增强合金蠕变过程中位错与第二相交互作用,提高合金的蠕变性能。     

Effect of addition of Si on microstructure,mechanical properties,bio-corrosion and cytotoxicity of Mg-6Al-1Zn alloy

The Mg-6Al-4Zn alloy was fabricated by mechanical alloying (MA) and hot pressing to serve as biodegradable metal implant. The influence of addition of 1% Si (mass fraction) on the microstructure, mechanical properties and bio-corrosion behavior of Mg-6Al-1Zn alloy was studied using X-ray diffractometry, transmission electron microscopy, compression test, as well as immersion, electrochemical test and MTT assay. The results showed that the addition of 1% Si to Mg-6Al-1Zn alloy led to the formation of fine Mg₂Si phase with polygonal shape, and increased compressive strength, elongation and improved corrosion resistance. Furthermore, the cell viability of Saos-2 cells has been improved by addition of 1% Si to Mg-6Al-1Zn alloy. According to the results, the magnesium ions released in the methylthiazol tetrazolium (MTT) test have not shown any cell toxicity. All these indicated that the addition of 1% Si improved the properties of Mg-6Al-4Zn alloy for using as a biodegradable implant.