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1.
研究了Mg-RE复合微合金化的双相Ni3Al(B)-Cr基金属间化合物熔盐腐蚀和力学性能,发现Mg-RE复合微合金化能降低Ni3Al(B)-Cr在LiCl-KCl熔盐中的阳极电流密度;同时能在不降低Ni3Al(B)-Cr屈服强度的条件下,提高延伸率近20%。  相似文献   

2.
用分子轨道和双自旋-轨道(双SO)耦合模型研究了MgO、AgCl和AgBr中掺杂Ni^2+(d^8)离子的EPRg因子。研究表明,由于配体Br(4p电子)有大的SO耦合系数和较强的共价性,其对AgBr:Ni^2+的g因子有重要的贡献。  相似文献   

3.
用分子轨道和双自旋-轨道耦合模型,研究了Ni^2+在AgCl和AgBr四角晶位中的EPR零场分裂和g因子,结果表明,不应忽略配体Br对AgBr:Ni^2+EPR参数(D,g)的贡献。  相似文献   

4.
采用反应法,将NiCl2与TiCl4负载于复合载体MgCl2-SiO2上,制得新型双过渡金属催化体系TiCl4-NiCl2/MgCl2-SiO2/Al(i-Bu)3。该催化剂用于乙烯气相聚合,当x(Ni)为12.5%时,催化剂效率最高,聚合动力学属衰减型。催化剂因含有镍化合物具有齐聚及原位共聚性能,得到的聚乙烯具有支化度为3.6-7.2支化数/1000C的中密度聚乙烯,且产物相对分子质量增大。  相似文献   

5.
用双自旋-轨道耦合模型研究了Cr3+在AgX(X=Cl,Br)四角晶位中的零场分裂D和g因子.研究表明,中心金属离子和配体(Cl,Br)对络合物EPR参量的贡献都应考虑.  相似文献   

6.
考察了AlEt_2Cl/t-BuCl引发体系的α-蒎烯阳离子聚合反应行为。结果表明,AIEt_2Cl单独不能引发α-蒎烯聚合,与t-BuCl复合后才具有引发活性,其引发活性随t-BuCl/AlEt_2Cl的不同而变化,质谱分析表明α-蒎烯聚合产物中存在t-BuCl残基(CH_3)_3C,证明t-BuCl参与了链的引发反应。进一步实验还表明,t-BuCl与AlEt_2Cl相互作用除生成活性物质BuAlEt_2Cl_2外,还有烷基化的产物AlEtCl_2,AlCl_3生成,聚合反应条件及引发剂加料方式对α-蒎烯转化率及聚合产物组成都有影响。  相似文献   

7.
利用二-(2-乙基已基)磷酸(HDEHP)、异丙醚和乙醚溶剂萃取In(Ⅲ),并测定了In(Ⅲ)在有机相和水相之间的分配比.In(Ⅲ)在HDEHP-HNO_3、HDEHP-HClO_4和异丙醚-HBr体系中的化学产额依次为95.2%,91.7%和89.2%,在1mL的InCl_3医用放射性核素制剂中,Cu,Fe和Ag杂素元素的含量依次不大于0.04μg,0.15μg和2.1μg。  相似文献   

8.
采用反应法,将NiCl_2与TiCl_4负载于复合载体MgCl_2-SOf_2上,制得新型双过渡金属催化体系TiCl_4-NiCl_2/MgCl_2-SiO_2/Al(i-Bu)_3.该催化剂用于乙烯气相聚合,当x(Ni)为12.5%时,催化剂效率最高,聚合动力学属衰减型.催化剂因含有镍化合物具有齐聚及原位共聚性能,得到的聚乙烯具有支化度为3.6~7.2支化数/1000C的中密度聚乙烯,且产物相对分子质量增大。  相似文献   

9.
用双自旋-轨道耦合模型研究了Cs_2NaYX_6(X=Cl,Br):Cr ̄3+的EPRg因子。计算表明,配体Br4p轨道对络离子(CrBr_6) ̄3-PRg因子的贡献不应忽略。解释了Cs_2NaYBr_6:Cr ̄3+的g因子移动为正值的疑惑。  相似文献   

10.
DMF中Nd—Ni合金膜的制备   总被引:2,自引:0,他引:2  
研究了室温下在含有少量水的NdCl3-NiCl2-DMF溶液中电沉积制备Nd-Ni功能合金膜,选定一系列的阴极电位进行恒电位电解,制备出不同Nd含量的Nd-Ni合金膜.EDAX和XRD分析表明:在0.10mol/dm3NdCl3+0.10mol/dm3NiCl2的DMF溶液中,控制电位为-1.75V(对SCE)进行恒电位电解,可得到有金属光泽、附着力强的银白色Nd-Ni合金膜  相似文献   

11.
在Nd2Fe14B稀土永磁体基体表面,采用磁控溅射(直流+射频)技术制备了Ti/Ni,Ti/Al和Al/Ni等二元合金薄膜和Ti/Al/Ni三元合金薄膜。并通过中性盐雾试验、腐蚀失重计算、电化学腐蚀试验、金相观察等方式,对比研究了不同表面处理对Nd2Fe14B稀土永磁体基体抗腐蚀性能的影响,并构建了腐蚀模型。研究发现:Ti/Ni,Ti/Al和Al/Ni等二元合金薄膜和Ti/Al/Ni三元合金薄膜均有效地提高了Nd2Fe14B稀土永磁体基体耐中性盐雾腐蚀和电化学腐蚀的能力;Ti/Al/Ni三元合金薄膜较Ti/Ni,Ti/Al和Al/Ni等二元合金薄膜有更优良的综合耐腐蚀性能,其磁控溅射工艺参数为:Ar流量60 sccm,基片温度常温,Ni,Al,Ti的溅射功率都为250 W,基片转速20 r·min-1,镀膜均速0.3 nm·s-1,总计溅射时间1 h。  相似文献   

12.
采用工业铝电解质体系,在Na3AlF6 Al2O3中加入TiO2,在熔融状态下电解,直接得到Al Ti合金·利用扫描电镜对产物的形貌和化学成分做了分析,结果表明实验可行,合金中Ti的质量分数可达到9%以上,超过已往文献报道·而且Ti与Al以化合物的形式存在·此类产品可作为母合金使用·对熔盐电解法制备Al Ti合金的机理作了初步探讨,认为与Al Si合金的形成具有相似的机理:Al还原了TiO2中的金属Ti,与预先放置的铝(阴极)构成Al Ti合金;Ti与Al同时在阴极析出,形成Al Ti合金·保持一定的条件,电解能够始终进行·  相似文献   

13.
Metal Sm has been widely used in making Al-Sm magnet alloy materials.Conventional distillation technology to produce Sm has the disadvantages of low productivity,high costs,and pollution generation.The objective of this study was to develop a molten salt electrolyte system to produce Al-Sm alloy directly,with focus on the electrical conductivity and optimal operating conditions to minimize the energy consumption.The continuously varying cell constant (CVCC) technique was used to measure the conductivity for the Na3AlF6-AlF3-LiF-MgF2-Al2O3-Sm2O3 electrolysis medium in the temperature range from 905 to 1055℃.The temperature (t) and the addition of Al2O3 (W(Al2O3)),Sm2O3 (W(Sm2O3)),and a combination of Al2O3 and Sm2O3 into the basic fluoride system were examined with respect to their effects on the conductivity (κ) and activation energy.The experimental results showed that the molten electrolyte conductivity increases with increasing temperature (t) and decreases with the addition of Al2O3 or Sm2O3 or both.We concluded that the optimal operation conditions for Al-Sm intermediate alloy production in the Na3AlF6-AlF3-LiF-MgF2-Al2O3-Sm2O3 system are W(Al2O3) + W(Sm2O3) =3wt%,W(Al2O3)∶ W(Sm2O3) =7∶3,and a temperature of 965 to 995℃,which results in satisfactory conductivity,low fluoride evaporation losses,and low energy consumption.  相似文献   

14.
熔盐电解法制取Al-Si合金   总被引:3,自引:1,他引:2  
按照工业铝电解生产的方式,采用Na3AlF6 Al2O3体系作为支持电解质,加入SiO2,在熔融状态下电解,得到Al Si合金·利用扫描电镜对产物的形貌和化学成分进行了分析,结果表明合金中Si的含量可达到30%以上,为过共晶产物·结晶Si的形貌是典型的针片状·此产品可作为母合金使用·根据实验结果,对熔盐电解法制备Al Si母合金的机理进行了讨论,认为Al Si合金的生成是由于两种机制共同作用的结果:Al还原了SiO2中的Si,构成Al Si合金;Si与Al同时在阴极析出,形成Al Si合金·保持Al2O3及SiO2的浓度,电解可始终进行·此法可以作为一种新的合金生产方式在实际中应用·  相似文献   

15.
Al_2O_3对激光熔覆镍基涂层腐蚀性的影响   总被引:1,自引:0,他引:1  
为研究不同Al2O3含量对激光熔覆镍基涂层耐腐蚀性能的影响.将基体与不同Al2O3含量的Al2O3/Ni熔覆层界面进行对比试验,利用SSX-500型扫描电镜对合金熔覆层的组织形貌进行观察,采用电化学腐蚀实验和盐雾实验对涂层的腐蚀性进行测试,结果表明,在镍基自熔合金粉末中加入Al2O3后,熔覆层的显微组织得到了细化.当Al2O3含量为40%时,致钝电流密度和维钝电流密度最小,钝化区范围最大;盐雾实验中涂层单位面积增重为1.15mg/mm2,较不加Al2 O3的Ni60合金涂层降低了约48.5%,耐蚀性能得到了显著提高.  相似文献   

16.
采用双探头符合技术测量Ni、Al、Zr、Nb、NiAl及Ni50Al48Zr2、Ni50Al48Nb2样品的正电子湮没辐射的多普勒展宽谱.从谱线提取正电子与样品中d电子湮没的信息,发现正电子与NiAl样品的d电子湮没信号因Ni3d-Al 3p电子杂化而相对降低,Zr、Nb的添加导致合金样品中d-d电子作用增强、谱线d电子信号增大,添加Nb的样品谱线峰高于添加Zr样品,说明Nb的加入比Zr抑制d-p电子作用效果更佳.  相似文献   

17.
Liquid structure of molten pure Cu, Cu-12Al, Cu-12Al-4Ni (mass fraction, %) alloys has been investigated using the X-ray diffraction method. It is found that the main peak of the structure factor of pure Cu is symmetrical. In the front of main peak, the curve takes on a shape of parabola, whereas a distinct pre-peak has been found around a scattering vector magnitude of 18.5 nm?1 in the structure factor of the liquid Cu-12Al alloy. This pre-peak increases its intensity with the addition of Ni in the liquid Cu-12Al-4Ni alloy. The appearance of a pre-peak is a mark of the mediate-range order. Based on Daken-Gurry theory and according to mutual interaction between unlike atoms, the analysis of correlation between different composition and liquid structure was done: the strong interaction exists between Cu and Ni, so Cu-Al can form strong chemical bond which causes compound-forming behavior. Therefore, the medium-range size clusters can form in melt. The presence of the pre-peak corresponds to these clusters. The addition of Ni can strengthen the interaction between unlike atoms and increase the sizes of clusters, thus result in the height of pre-peak increasing.  相似文献   

18.
应用Kissinger公式计算得到Al_(85)Ni_(10)Er_5非晶合金初始晶化激活能Ex为104 k J/mol.计算了Al_(85)Ni_(10)Er_5非晶合金的拓扑不稳定参数λ=0.087,说明合金是铝基纳米晶合金.Al_(85)Ni_(10)Er_5非晶合金第一放热峰的晶化体积分数与温度的关系曲线均呈"S"形,随升温速率的增加,这种"S"形曲线均向高温处移动.合金晶化第一阶段的晶化激活能Ea(x)与晶化体积分数呈线性递减趋势.此外,晶化体积分数在10%~50%阶段的激活能Ea(x)大于合金初始晶化激活能Ex,这是由于非晶合金内稳定的无序原子团簇结构有效地抑制了初生晶相长大的结果.  相似文献   

19.
Liquid structure of molten pure Cu, Cu-12Al, Cu-12Al-4Ni (mass fraction, %) alloys has been investigated using the X-ray diffraction method. It is found that the main peak of the structure factor of pure Cu is symmetrical. In the front of main peak, the curve takes on a shape of parabola, whereas a distinct pre-peak has been found around a scattering vector magnitude of 18.5 nm-1 in the structure factor of the liquid Cu-12Al alloy. This pre-peak increases its intensity with the addition of Ni in the liquid Cu-12Al-4Ni alloy. The appearance of a pre-peak is a mark of the mediate-range order. Based on Daken-Gurry theory and according to mutual interaction between unlike atoms, the analysis of correlation between different composition and liquid structure was done: the strong interaction exists between Cu and Ni, so Cu-Al can form strong chemical bond which causes compound-forming behavior. Therefore, the medium-range size clusters can form in melt. The presence of the pre-peak corresponds to these clusters. The addition of Ni can strengthen the interaction between unlike atoms and increase the sizes of clusters, thus result in the height of pre-peak increasing.  相似文献   

20.
采用LMTO CPA方法,计算了NiAl合金(B2结构)在成分无序情况下的热力学性质,并讨论了NiAl合金的偏析现象·理论结果表明,当Ni的成分小于35%(原子分数)时,则NiAl合金表面出现Al的偏析现象,当Ni的成分大于35%(原子分数)时,则出现Ni的偏析现象·  相似文献   

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