Effect of Cerium on Mechanical Properties and Morphology of ZZn4-1 Alloy

ＺＡａｌｌｏｙｓｂｅｌｏｎｇｔｏｃａｓｔｚｉｎｃａｌｌｏｙｆａｍｉｌｙｄｅｖｅｌｏｐｅｄｂｙＣａｎａｄｉａｎａｎｄＡｍｅｒｉｃａｎｒｅｓｅａｒｃｈｅｒｓｉｎｍｉｄ1970ｓ.ＺＡａｌｌｏｙｓａｒｅｏｆｇｏｏｄｃａｓｔｉｎｇａｎｄｐｒｏｃｅｓｓｉｎｇｐｒｏｐｅｒｔｉｅｓａｎｄａｒｅｗｉｄｅｌｙｕｓｅｄｉｎｄｉｆｆｅｒｅｎｔｆｉｅｌｄｓ[1].ＨｙｐｏｅｕｔｅｃｔｉｃＺＺｎ41ａｌｌｏｙ,ａｓａｎｉｍｐｏｒｔａｎｔｍｅｍｂｅｒｏｆＺＡａｌｌｏｙｆａｍｉｌｙ,ｉｓｏｆｇｏｏｄｃａｓｔａｂｉｌｉｔｙａｎｄｔｈｕｓｉ…     

Effect of Yttrium Addition on Microstructures and Room Temperature Tensile Properties of Ti-47Al Alloy

The microstructures and room temperature tensile properties of a series of Ti-47Al-xY （x = 0%, 0.1%, 0.3%, 0.5%, 0.7% and 1.0%（atom fraction）） were investigated systemically. Results show that both the grain size and lamellar spacing decrease remarkably with the increase of Y content. When the content of Y is greater than 0.1%, most of the Y elements accumulate along the grain boundaries and some fine particles are uniformly dispersed within the grains in the form of YAl2 compound because of the low solubility and segregation of Y in TiAl alloys. Grain-boundary seg- regation of Y element is more prominent with the increase of Y addition. Good tensile properties are obtained when Y addition ranges from 0.3 % to 0.5 %. The refinement of grain and lamellar structures and dispersion of YAl2 within the grains contribute to the improvement of tensile properties. On the other hand, for high Y-added alloys （over 0.5% Y）, tensile properties are obviously deteriorated due to brittle cleavage fracture of the coarse YAl2 network.     

Effects of Cerium on Microstructures and Mechanical Properties of Zn-22%Al Vibration Damping Alloy

Effects of Cerium on Microstructures and Mechanical Properties of Zn-22%Al Vibration Damping Alloy     

稀土铈对化学沉积Co-Ni-B合金镀层结构和性能的影响

研究了稀土铈对化学沉积Co-Ni-B合金层化学组成、结构和性能的影响。结果表明：微量稀土铈的加入提高了镀层中钴的含量，降低了镍和硼的含量；使镀层由非晶态转变为品态；稀土铈也明显地提高了镀层的显微硬度，在一定的范围内，镀液中稀土铈添加量越多，镀层的铈含量和显微硬度也越高；稀土铈还提高了镀层的饱和磁化强度，降低了剩余磁化强度和娇顽力，含铈镀层显示出了良好的软磁性能。     

硼对Ni-46Ti-4Al合金微观组织和力学性能的影响

采用电子探针、透射电镜和X射线衍射方法研究了添加微量B元素(0～1%)(质量分数)对Ni-46Ti-4Al合金微观组织的影响,并采用力学压缩试验测试了合金的室温和高温力学性能.结果表明,Ni-46Ti-4Al合金由NiTi基体和(Ti,Al)<,2>Ni两相组成.添加微量B元素(0.02%)可以促使Ni-46Ti-4Al合金中出现TiB<,2>化合物,且与(Ti,Al)<,2>Ni相都在晶界上析出.随着B含量增加,(Ti,Al)<,2>Ni相逐渐减少,TiB<,2>相逐渐增多.这两相的硬度均高于NiTi基体相,是合金中的强化相.添加适量的B可以显著提高Ni-46Ti-4Al合金的室温和高温屈服强度,例如:添加l%B合金的室温屈服强度达到2553 MPa,比Ni-46Ti-4Al合金提高了128%.添加0.02%B和1%B合金在600℃时的屈服强度分别为382和498 MPa,比Ni-46Ti-4Al合金提高了35%和70%.合金屈服强度和两个强化相((Ti,Al)<,2>Ni和TiB<,2>相)的总体积分数成正比.B加入后一方面使Ni-46Ti-4Al合金得到固溶强化,另一方面,还促使生成具有强化作用的TiB<,2>相,这是合金室温和高温屈服强度提高的主要原因.     

Effect of ErCl3 Addition on Microstructures and Properties of AZ91 Magnesium Alloy

Effect of ErCl_3 Addition on Microstructures and Properties of AZ91 Magnesium Alloy     

Effect of Cerium on the Viscosity of Liquid Fe-C Alloy of Eutectic Content

The viscosities of liquid Fe-4.30C and Fe-4.30C-Ce alloys were measured by oscillating crucible viscometer. The results show that viscosity of Fe-4.30C alloy changes from 5.50 to 8.30 MPa~s when the liquid is cooled from 1425℃ to the melting point. The abnormity of viscosity of Fe-4.30C alloy near the melting point is reasonable due to the formation of graphite. The addition of cerium especially with content higher than 0.21% causes an evidently decrease in viscosity for eutectic alloy resulting from increase of free volume and size decrease of atom cluster in the liquids. It can be concended that the existence of C-Ce compound contributes to the discontinuous of viscosity at 1340 ～ 1370 ℃ for the Fe-4.30C-Ce alloy by experinments with differential scanning calorimeter.     

钇对Ti-43Al-9V合金组织性能的影响

采用OM，XRD，SEM和TEM等测试方法，分析了稀土元素(Y)对Ti—43Al—9V合金显微组织以及力学形能的影响。实验结果表明，Ti—43Al—9V—0．3Y合金由γ相、α2相、B2相和YAl2相组成；添加稀土可以细化Ti—43Al—9V合金的晶粒尺寸，并促进细小的α2／γ层片形成以及细化粗大的α2／γ／B2层片。对TiAl合金力学性能测试表明，适量添加稀土Y(0．3％，原子分数)可明显改善合金的室温强度和塑性，但过量添加将会造成材料性能降低；断口分析表明过量添加稀土导致沿晶断裂比例增加将损害TiAl合金的性能。     

Influence of Cerium on Corrosion of AZ91 Magnesium Alloy

Effect of cerium addition on corrosion resistance of AZ91 magnesium alloy was investigated using the static weight loss and polarization curve method as well as metallographical observation. The results indicate that a small amount of cerium （0.2% - 0.8%） in AZ91 magnesium alloy can significantly reduce the corrosion rate, enhance the electrode voltage and lower corrosion current density in 3.5%NaCl aqueous solution, and AZ91-0.8% Ce alloy has better corrosion resistant performance. The reason for increasing corrosion resistance is attributed to the addition of Ce, refining the α-Mg grain, reducing the segregation of element Al, and improving the morphologies of β-Mg17 Al12 phases.     

Effect of Yttrium and Cerium Addition on Microstructure and Mechanical Properties of AM50 Magnesium Alloy

To develop magnesium alloy with low cost, high strength and excellent elevated temperature properties, effect of Y and Ce addition on microstructure and mechanical properties of AM50 magnesium alloy was studied. Result showed that addition of small amount of Y and Ce to AM50 alloys resulted in refinement of microstructure. Owing to the improvement of microstructure, the mechanical properties of alloys at both ambient and elevated temperature were increased. AM50 alloy containing 0.6 % Ce-0.3 % Y （mass fraction） had good refinement effect and relatively ideal mechanical properties.     

Effect of Neodymium on As-Cast Microstructure and Mechanical Properties of AZ31 Wrought Alloy

Nd in the form of powder or intermediate alloy was added to AZ31 wrought alloy. The as-obtained alloy was characterized and tested with respect to its microstructure and mechanical properties. The relationship between the microstructure, mechanical properties and tensile fracture mechanism were discussed, with relevant alloys as reference for comparison. Experimental results show that the same quantity of Nd was added into AZ31 in powder form or in intermediate alloy, the absorption rate of Nd reached only 10.8% for the former case and as high as 95% for the later case. Pure Nd powder was added, no new compound was detected, but it served as reductant and purified alloy melt, resulting in improving the tensile strength while Nd was added into AZ31 as Mg-Nd intermediate alloy. The compound Al2Nd and Mg12 Nd were formed in magnesium alloy, which were distributed in the matrix in the shapes of strip and particle, evidently refined the as-cast structure. The as-cast tensile strength (228MPa) of adding pure Nd powder approximated to the figure (245MPa) of adding Mg-Nd intermediate alloy. The tensile fracture mchanism of as-cast AZ31 transformed from cleavage fracture into quasi-cleavage fracture.     

Microstructures and Properties of Melt-Spun and As-Cast Mg-20Gd Binary Alloy

Mg-20Gd（ %, mass fraction）samples were prepared using melt-spinning and copper mold casting techniques. Microstructures and properties of the Mg-20Gd were investigated. Results show that the melt-spun ribbon is mainly composed of supersaturated a-Mg solid solution phase and the as-cast ingot mainly contains a-Mg solid solution and MgsGd phase. The differential scanning calorimeter （DSC） curve of the ribbon exhibits a small exothermic peak in the temperature range from 630 to 680 K, which indicates that the ribbon contains a metastable phase （amorphous）. Tensile strength at room temperature of the melt-spun ribbon and as-cast specimen are 308 and 254 MPa, respectively. The elongations of the two samples are less than 2 %. The fracture surfaces demonstrate that the fracture mode of the as-cast Mg-20Gd is a typical cleavage fracture and that of the melt-spun sample is a combination of brittle fracture and ductile fracture.     

Effect of Cerium on Chemical Short Range Order of Al-Fe-Ce Amorphous Alloy

Ｉｎｒｅｃｅｎｔｙｅａｒｓ,Ｈｅｅｔａｌ.[1]ａｎｄＩｎｏｕｅｅｔａｌ.[2]ｄｉｓｃｏｖｅｒｅｄａｇｒｏｕｐｏｆａｍｏｒｐｈｏｕｓａｌｌｏｙｓｗｉｔｈａｌｕｍｉｎｕｍｃｏｎｔｅｎｔｃｌｏｓｅｔｏ90%(ａｔｏｍｆｒａｃｔｉｏｎ),ｗｈｉｃｈｐｏｓｓｅｓｓｅｘｃｅｌｌｅｎｔｓｐｅｃｉｆｉｃｓｔｒｅｎｇｔｈｉｎＡｌＴＭＲＥ(ＴＭ=ｔｒａｎｓｉｔｉｏｎｍｅｔａｌ)ｓｙｓｔｅｍｓ.Ｔｈｅｙｈａｖｅｕｐｔｏ500～1100ＭＰａｉｎｓｔｒｅｎｇｔｈａｎｄｇｏｏｄｄｕｃｔｉｌｉｔｙ.Ｈｏｗｅｖｅｒ,ｔｈｅｏｒｉｇｉｎｏｆＡｌｂａｓ…     

Effect of cerium on microstructure,wetting and mechanical properties of Ag-Cu-Ti filler alloy

Effect of cerium on microstructure,mechanical and wetting properties of Ag-Cu-Ti filler alloy was researched with optical microscopy,scanning electron microscopy and X-ray diffraction.The results indicated that addition of cerium accelerated alloying of the filler alloy,enlarged supercooled region,caused microstructural refinement and dispersed distribution of intermetallic compounds.It resulted in the increase in microhardness and shear strength of Ag-Cu-Ti filler alloy.At the same time,cerium improved wet...     

铈对铸造镁合金AZ91D显微组织与力学性能的影响

利用光学金相显微镜OM和XRD分析了分别加入0．1％，0．3％，0．5％，0．7％和1．0％Ce的AZ91D合金显微组织和相组成，测试了室温力学性能和硬度。结果表明，加入一定量Ce后的AZ91D合金形成杆状化合物Al4Ce，被推移到生长界面，阻碍枝晶的自由生长，从而细化合金显微组织；Ce能提高AZ91D合金室温抗拉强度和硬度，而对其屈服强度和延伸率影响不大；加入0．7％Ce的AZ91D合金晶粒细化效果好，其综合力学性能比较理想。     

Effects of Y and Ce on Microstructures and Properties of Nb-Si System Composites

The effects of yttrium and cerium on microstructures and properties of Nb-Si system composites were investigated by scanning electron microscopy( SEM), energy dispersive spectrum(EDS), X-ray diffraction(XRD) and high temperature oxidation experiments.It is found that the coarse primary silicide phase became finer and more homogeneous with Y and Ce addition.The results of high temperature oxidation experiments show that the oxidation rates of NbSi system composites with an appropriate amount of Y and Ce decrease compared with those of alloys without Y or Ce addition, and oxidation products mainly distribute along the phase boundaries between the Nb solid solution and silicide.     

Effect of Cerium on Microstructure and Electrochemical Performance of Ti-V-Cr-Ni Electrode Alloy

Effect of cerium on the microstructure and electrochemical performance of the Ti0.25V0.35-xCexCr0.1Ni0.3（x=0,0.005）electrode alloy was investigated by X-ray diffraction（XRD）,field emission scanning electron microscopy/energy dispersive X-ray spectrometry（FESEM-EDS）,and electrochemical impedance spectroscopy（EIS）measurements.On the basis of XRD and FESEM-EDS analysis,the alloy was mainly composed of V-based solid solution with body-centered-cubic structure and TiNi-based secondary phase.Ce did not exist in two phases,instead,it existed as Ce-rich small white particles,with irregular edges,distributed near the grain boundaries of the V-based solid solution phase.Discharge capacity,cycle stability,and high-rate discharge ability of the alloy electrode were effectively improved with the addition of Ce at 293 K.It was very surprising that the charge retention was abnormal with larger discharge capacity after standing at the open circuit for 24 h.EIS indicated that addition of Ce improved the dynamic performance,which caused the charge transfer resistance（RT）to decrease and exchange current density（I0）to increase markedly.The exchange current density of the electrochemical reaction on the alloy surface with Ce addition was about 2.07 and 3.10 times larger than that of the alloy without Ce at 303 and 343 K,respectively.The diffusion coefficient of hydrogen（D）in the bulk alloy electrode decreased with addition of Ce,but it did not decrease so much,and the apparent activation energy（△rH）was far higher than that of the AB5 type alloy.     

Influences of Cerium and Carbide on Mechanical Properties of Steels

Ｉｔｗａｓｔｈｏｕｇｈｔｔｈａｔｔｈｅｒａｒｅｅａｒｔｈｓｗｅｒｅｎｏｔｃａｒｂｉｄｅｆｏｒｍｉｎｇｅｌｅｍｅｎｔｓｂａｓｅｄｏｎｔｈｅｆａｃｔｔｈａｔｔｈｅｒａｒｅｅａｒｔｈｓｒｅａｃｔｏｎｃａｒｂｏｎｉｎｓｔｅｅｌｓｉｍｉｌａｒｌｙｔｏｓｉｌｉｃｏｎ ,ｔｈｅｅｌｅｍｅｎｔｗｈｉｃｈｎｅｖｅｒｆｏｒｍｓｃａｒｂｉｄｅａｎｄｉｓｄｉｆｆｅｒｅｎｔｆｒｏｍｔｈｅｅｌｅ ｍｅｎｔｓｓｕｃｈａｓｃｈｒｏｍｉｕｍ ,ｍａｎｇａｎｅｓｅａｎｄｔｕｎｇ ｓｔｅｎｗｈｉｃｈｆｏｒｍｃａｒｂｉｄｅｓ .Ｍｏｒｅｏｖｅ…     

Effect of Cerium on Activity of α-Amylase from Porcine Pancreas

Ｒａｒｅｅａｒｔｈｓｃａｎａｆｆｅｃｔｃｈｌｏｒｏｐｌａｓｔｕｌｔｒａ ｓｔｒｕｃｔｕｒｅ[1～ 3 ] ａｎｄｅｎｚｙｍｅａｃｔｉｖｉｔｙ[4～ 7] ,ｂｙｗｈｉｃｈｏｆｌｏｗｃｏｎｃｅｎｔｒａｔｉｏｎ ,ｂｉｏｌｏｇｉｃａｌｆｕｎｃ ｔｉｏｎｓａｒｅａｃｃｅｌｅｒａｔｅｄ ,ｂｕｔｒｅｓｔｒａｉｎｅｄａｔｈｉｇｈｃｏｎｃｅｎｔｒａｔｉｏｎ .α Ａｍｙｌａｓｅ ,ｗｈｉｃｈｂｉｎｄｓ 4ｏｒ 5ｃａｌｃｉｕｍｉｏｎｓｉｎｆｏｒｍｏｆｄｉｐｏｌｙｍｅｒ[7] ,ｐｌａｙｓａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｔｈｅｃｏｕｒｓｅｏ…