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1.
Effect of Cerium on Chemical Short Range Order of Al-Fe-Ce Amorphous Alloy   总被引:1,自引:0,他引:1  
Inrecentyears,Heetal.[1]andInoueetal.[2]discoveredagroupofamorphousalloyswithaluminumcontentcloseto90%(atomfraction),whichpossessexcellentspecificstrengthinAlTMRE(TM=transitionmetal)systems.Theyhaveupto500~1100MPainstrengthandgoodductility.However,theoriginofAlbas…  相似文献   

2.
StudyonAnnealingEmbritlementofFe┐B┐SiAmorphousAloyCaoXingguo①,GuoZechen①,CheXiaozhou②,LiuPing①,YinBiao①ABSTRACTThelawandactiv...  相似文献   

3.
Effect of Cerium on the Properties of CuPNiSn Amorphous Alloys   总被引:1,自引:0,他引:1  
CuPNiSn amorphous alloys are good brazing materials at medium temperature for replacementof silver bearing brazing materials.The crystallization temperature,wettability,tensile strength of Cu-Cujoints and the microstructure of joints for three compositional series are reported.Some rare earth elementswere added in two series.It has been found that grains are refined and the tensile strengths increase as in-creasing rare earth content.The results also show that the brittle fracture turns to plastic one for the jointswith reducing amount of(Ni+Sn),and the tensile strength is increased.  相似文献   

4.
Effect of Cerium on Gas Evolution Behavior of Pb-Ca-Sn Alloy   总被引:1,自引:0,他引:1  
Hydrogen and oxygen evolution reactions areharmful to the valve regulate lead acid battery duringcharging and discharging processes.Oxygen evolutionreaction occurs at the positive electrode in the leadacid battery and transfers from baffle to the negativeelectrode,reducing to water finally.Hydrogen evolu-tion reaction takes place occasionally on the negativeelectrode inthe lead acid battery.In general,the rateof hydrogen oxidation reaction on the negative elec-trode is lower or less hydrogenis…  相似文献   

5.
The effects of B and Ce on the removal of inclusions, microstructures, and properties of Cu-Fe-P alloys were studied. Certain impurity elements and the microstructures, mechanical properties, and conductivity of four experimental alloys, Cu-0.22Fe-0.06P, Cu-0.22Fe-0.06P-0.05Ce, Cu-0.22Fe-0.06P-0.02B, and Cu-0.22Fe-0.06P-0.05Ce-0. 02B ( %, mass fraction), were tested and analyzed. Results show that on one hand, B and Ce have a remarkable function of removing S, Pb, and Bi from copper alloys ; on the other hand, the recrystallization temperature of the Cu-Fe-P alloy is considerably increased by adding trace B and Ce, resulting in the combined strengthening effect of precipitation hardening and cold work hardening after cold working and aging, while the negative effect of B and Ce on conductivity is slight. Therefore, a good combination of high strength and conductivity is achieved.  相似文献   

6.
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.  相似文献   

7.
Effect of Cerium on the Viscosity of Liquid Fe-C Alloy of Eutectic Content   总被引:1,自引:0,他引:1  
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.  相似文献   

8.
A series of Ce-doped Ni-B amorphous alloy catalysts were prepared by a KBH4 reduction method, characterized by ICP, BET, XRD, H2-chemisorption, H2-TPD, etc., and tested in the hydrogenation of 2-ethylanthraquinone. The results of characterization show that with the addition of Ce the amount of H2-chemisorption and H2-TPD areas first increases markedly and then decreases with the maximum appears at the atomic ratio of Ce to Ni of 0.036. The hydrogenation activity also shows the same trend. The effects of Ce are attributed to its dispersion of Ni particles, resulting in the formation of more surface Ni centers. However, much higher Ce contents may result in the decrease of the surface Ni contents. After heat treatment at higher temperatures, the amorphous structure of Ni-B is destroyed.  相似文献   

9.
EffectofCeriumonLithium-AluminiumAnodeGuanCongsheng(管从胜),DuanShuzhen(段淑贞),ZhaoGuangwen(招光文)(DepartmentofPhysicalChemistry,Uni...  相似文献   

10.
Benzene selective hydrogenation to cyclohexenehas aroused considerable interest among both indus-tries andresearchers as well inthe hope of establishinga new process for producing cyclohexanol via cyclo-hexene hydration .Cyclohexanol is the basic rawmate-rial in the production of polyamides nylon-66 , whichis produced by the polymerization of adipic acid withhexamethylendiamine .In this process ,the theoreticalconsumption of hydrogen is reduced to one-third andfewundesirable by-products are fo…  相似文献   

11.
本文研究Fe80B20-xSix(x=6,8,10,12)非晶态合金的退火脆性规律,给出了合金成分原料纯度,薄带厚度以及薄带表面状态对非晶态合金退火脆性的影响。铁基非晶态合金在低温退火过程中已明显变脆。这种退火脆性是由非晶态合金亚稳特性决定的结构弛豫所致。  相似文献   

12.
本文研究了B和Si的含量及Fe/(B+Si)相对含量对非晶态Fe-B-Si合金退火脆化行为的影响;分析了在常规热处理条件下,利用成分的变化,获得延性与磁性综合性能的可能性。实验结果表明,非晶态Fe-B-Si合金的退火脆化行为具有较大的成分依赖性,位于Fe79at%-81at%,B11at%,Si8at%-9at%成分范围内的Fe-B-Si非晶态合金的退火脆化敏感性最小,脆化仍发生于晶化开始之前...  相似文献   

13.
应用电子显微镜、X射线衍射技术,对低温长期使用的铁铬铝电热合金进行分析。结果表明:晶粒长大以及铬原子含量为75%左右的铁铬二元α'相在晶界和基体中析出,是导致合金变脆的主要原因;通常微量碳化物Cr23C6相以及σ相总是沿晶界分布。  相似文献   

14.
ZAalloysbelongtocastzincalloyfamilydevelopedbyCanadianandAmericanresearchersinmid1970s.ZAalloysareofgoodcastingandprocessingpropertiesandarewidelyusedindifferentfields[1].HypoeutecticZZn41alloy,asanimportantmemberofZAalloyfamily,isofgoodcastabilityandthusi…  相似文献   

15.
本文综合论述了非晶态合金的脆化,尤其是非晶态软磁合金的退火脆化;分析了非晶合金退火脆化的起因和影响因素;并对解决合金退火脆化问题的途径进行了探讨。  相似文献   

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