The effect of rare earth metals cerium, lanthanum and yttrium on chemical composition, structure and properties of electroless Co B alloy coating was studied. By plasma transmitting spectrograph, electron energy spec...The effect of rare earth metals cerium, lanthanum and yttrium on chemical composition, structure and properties of electroless Co B alloy coating was studied. By plasma transmitting spectrograph, electron energy spectrometer, X ray diffractometter, micro hardometer and vibratory sample magnetometer the chemical constitution, structure and properties of the alloy coatings were analyzed and inspected. The results show that with a tiny quantity of rare earth metal added into Co B alloy coating, the content of boron is decreased in the alloy coatings, and the kinds of rare earth metal have enormous effect on the structure and properties of electroless Co B alloy coating. At the same time electroless Co B alloy with amorphous structure is transformed to electroless Co B RE alloy with microcrystalline or crystalline structure. In this way microhardness of the coatings is increased remarkably. Cerium and lanthanum would also increase the saturated magnetic intensity and decrease coercitive force of the coating. So soft magnetization of the coatings would be improved.展开更多
By plasma transmitting spectrograph,electron energy spectrometry,X-ray diffractometry,transmission electron microscopy and micro-hardometry,the effects of ultrasonic irradiation and rare earth metal cerium on the depo...By plasma transmitting spectrograph,electron energy spectrometry,X-ray diffractometry,transmission electron microscopy and micro-hardometry,the effects of ultrasonic irradiation and rare earth metal cerium on the depositing speed,chemical composition,crystal structure and microhardness of electroless Co-Ni-B alloy coating were inspected and analyzed. The results show that cerium and ultrasonic irradiation can evidently raise the depositing speed of electroless Co-Ni-B alloy. The cerium content of electroless Co-Ni-B-Ce alloy coating also increases after ultrasonic irradiation applied to electroless Co-Ni-B plating process. Under the action of ultrasonic irradiation and rare metal cerium,the chemical composition of electroless Co-Ni-B alloy coating is changed. Electroless Co-Ni-B alloy with amorphous structure is transformed to electroless Co-Ni-B-Ce alloy with microcrystalline in general state and electroless Co-Ni-B-Ce alloy with crystalline structure in ultrasonic irradiation. In this way microhardness of the coatings increases remarkably.展开更多
Developing high-performance electromagnetic absorbing materials remains a challenge.In this work,Gd-Co ferrite@carbon core-shell structure composites were synthesized by a two-step hydrothermal method.The effects of r...Developing high-performance electromagnetic absorbing materials remains a challenge.In this work,Gd-Co ferrite@carbon core-shell structure composites were synthesized by a two-step hydrothermal method.The effects of rare earth Gd doping amount on the microstructure and electromagnetic wave absorption properties of cobalt ferrite@carbon composites were mainly studied.The results show that an appropriate amount of Gd doping can refine the crystal grain size of cobalt ferrite@carbon composites.However,when the doping amount of Gd exceeds the solid solubility threshold,the secondary phase GdFeO_(3)will be generated and the grain size will increase.When the doping amount of Gd is x=0.04,the reflection loss(RL) of the CoFe_(1.96)Gd_(0.04)O_(4)@C composites reaches the minimum value of -9.26 dB at the absorption layer thickness of 2.0 mm and a frequency of 13.67 GHz,and the effective absorption band(EAB) is 5.01 GHz(10.95-15.96 GHz).Compared with the CoFe_(2)O_(4)@C composites,the RL of the CoFe_(1.96)Gd_(0.04)O_(4)@C composites is increased by 79.35%,and the EAB is broadened by 3.51%.Gd ions enhance the dielectric loss through the grain size effect,and the increase of magnetocrystalline anisotropy enhances the magnetic loss.The CoFe_(1.96)Gd_(0.04)O_(4)@C composites have excellent impedance matching,which relies on the strong magnetic loss of ferrite,the interface polarization,and dipole polarization formed by the carbon shell to attenuate electromagnetic waves.展开更多
利用恒电位仪、等离子发射光谱仪、电子能谱仪、X射线衍射仪、透射电子显微镜等考察和分析了引入稀土金属La时化学镀Co Fe B合金的阴极极化曲线、沉积速度、化学成分和晶体结构。结果表明 ,稀土La的介入明显改善了化学镀Co Fe B合金的...利用恒电位仪、等离子发射光谱仪、电子能谱仪、X射线衍射仪、透射电子显微镜等考察和分析了引入稀土金属La时化学镀Co Fe B合金的阴极极化曲线、沉积速度、化学成分和晶体结构。结果表明 ,稀土La的介入明显改善了化学镀Co Fe B合金的静止电位和极化度 ,随镀液里稀土金属La添加量的增加 ,合金的沉积速度和镀层中La的含量都是先增后降 ,且都在La加入 0 6g·L- 1 时达到最大值。稀土La的介入使化学镀Co Fe B La合金镀层中B的含量减少 ,Co和Fe的含量增加 ,并使具有非晶态结构的化学镀Co Fe B合金转化为晶态结构的化学镀Co Fe B La合金。展开更多
利用等离子发射光谱仪、电子能谱仪、X射线衍射仪、透射电子显微镜和显微硬度计等考察和分析了引入超声波和稀土金属铈时化学镀Co Ni B合金镀液的沉积速度、Co Ni B合金镀层的化学成分、晶体结构和显微硬度。结果表明 ,超声波和稀土金...利用等离子发射光谱仪、电子能谱仪、X射线衍射仪、透射电子显微镜和显微硬度计等考察和分析了引入超声波和稀土金属铈时化学镀Co Ni B合金镀液的沉积速度、Co Ni B合金镀层的化学成分、晶体结构和显微硬度。结果表明 ,超声波和稀土金属铈的介入明显提高了化学镀Co Ni B合金的沉积速度 ,超声波的介入则提高了化学镀Co Ni B Ce合金镀层中稀土铈的含量。在超声波和稀土铈的共同作用下 ,化学镀Co Ni B合金镀层的化学组成发生了改变 ,镀层结构由非晶态向微晶和晶态转化 。展开更多
利用恒电位仪、等离子发射光谱仪、电子能谱仪、X射线衍射仪、透射电子显微镜等研究了在常态和磁场条件下化学镀Co Ni B Ce合金的电化学性质、化学组成和组织结构。结果表明 ,微量稀土和磁场的介入改善了化学镀Co Ni B合金的静止电位和...利用恒电位仪、等离子发射光谱仪、电子能谱仪、X射线衍射仪、透射电子显微镜等研究了在常态和磁场条件下化学镀Co Ni B Ce合金的电化学性质、化学组成和组织结构。结果表明 ,微量稀土和磁场的介入改善了化学镀Co Ni B合金的静止电位和极化度 ;随镀液里稀土金属Ce量的增加 ,化学镀Co Ni B Ce合金镀层中的Ce含量是先增加后下降 ,均在Ce的质量浓度为 0 8g/L时达到最大值。在磁场和稀土铈的作用下 ,化学镀Co Ni B Ce合金镀层中B的含量减少 ,Co和Ni的含量增加 ,因而在常态下非晶态的Co Ni B镀层转变成了微晶结构的Co Ni B Ce镀层 ,在磁场条件下含稀土Ce的镀层则发生了晶化转变。展开更多
借助等离子发射光谱、电子能谱仪、X 射线衍射仪、显微硬度计、磨损试验机和振动样品磁强计等分析了超声波对化学沉积Co Fe B Ce合金涂层化学成分、晶体结构、显微硬度、磨损体积和磁性能的影响。结果表明 ,在超声波的作用下 ,化学沉积C...借助等离子发射光谱、电子能谱仪、X 射线衍射仪、显微硬度计、磨损试验机和振动样品磁强计等分析了超声波对化学沉积Co Fe B Ce合金涂层化学成分、晶体结构、显微硬度、磨损体积和磁性能的影响。结果表明 ,在超声波的作用下 ,化学沉积Co Fe B Ce合金涂层中Co和Ce含量提高 ,Fe和B的含量则降低 ,而且具有微晶结构的化学沉积Co Fe B Ce合金涂层转变成了晶态结构的涂层。超声波的空化作用还明显地提高了化学沉积Co Fe B Ce合金涂层的显微硬度、耐磨性、饱和磁化强度与磁导率 ,降低了涂层的矫顽力 ,改善了涂层的软磁性能。展开更多
Phase equilibria of the R-Fe-Co pseudoternary system with R≤33.3%(mole fraction, R=Sm 0.5Dy 0.5) were determined in an isothermal section at 1 073 K and a vertical section of RFe 2-RCo 2 by using OM, X-ray diffractom...Phase equilibria of the R-Fe-Co pseudoternary system with R≤33.3%(mole fraction, R=Sm 0.5Dy 0.5) were determined in an isothermal section at 1 073 K and a vertical section of RFe 2-RCo 2 by using OM, X-ray diffractometer, EPMA DTA techniques. There are seven intermetallic phases: (Sm, Dy)(Fe, Co) 2, (Sm, Dy)(Fe, Co) 3, (Sm, Dy) 6(Fe, Co) 23, (Sm, Dy) 2(Fe, Co) 7, (Sm, Dy)(Fe, Co) 5, Th 2Ni 17-type and Th 2Zn 17-type (Sm, Dy) 2(Fe, Co) 17. The (Sm, Dy) 6(Fe, Co) 23 phase dissolves 36% Co(mole fraction) at 1 073 K. However, the (Sm, Dy) 2(Fe, Co) 7 phase in R 2(Fe 1-xCo x) 7 alloys dissolves about 19% Fe(mole fraction) at 1 073 K.展开更多
文摘The effect of rare earth metals cerium, lanthanum and yttrium on chemical composition, structure and properties of electroless Co B alloy coating was studied. By plasma transmitting spectrograph, electron energy spectrometer, X ray diffractometter, micro hardometer and vibratory sample magnetometer the chemical constitution, structure and properties of the alloy coatings were analyzed and inspected. The results show that with a tiny quantity of rare earth metal added into Co B alloy coating, the content of boron is decreased in the alloy coatings, and the kinds of rare earth metal have enormous effect on the structure and properties of electroless Co B alloy coating. At the same time electroless Co B alloy with amorphous structure is transformed to electroless Co B RE alloy with microcrystalline or crystalline structure. In this way microhardness of the coatings is increased remarkably. Cerium and lanthanum would also increase the saturated magnetic intensity and decrease coercitive force of the coating. So soft magnetization of the coatings would be improved.
文摘By plasma transmitting spectrograph,electron energy spectrometry,X-ray diffractometry,transmission electron microscopy and micro-hardometry,the effects of ultrasonic irradiation and rare earth metal cerium on the depositing speed,chemical composition,crystal structure and microhardness of electroless Co-Ni-B alloy coating were inspected and analyzed. The results show that cerium and ultrasonic irradiation can evidently raise the depositing speed of electroless Co-Ni-B alloy. The cerium content of electroless Co-Ni-B-Ce alloy coating also increases after ultrasonic irradiation applied to electroless Co-Ni-B plating process. Under the action of ultrasonic irradiation and rare metal cerium,the chemical composition of electroless Co-Ni-B alloy coating is changed. Electroless Co-Ni-B alloy with amorphous structure is transformed to electroless Co-Ni-B-Ce alloy with microcrystalline in general state and electroless Co-Ni-B-Ce alloy with crystalline structure in ultrasonic irradiation. In this way microhardness of the coatings increases remarkably.
基金financially supported by the National Natural Science Foundation of China (No.51372108)。
文摘Developing high-performance electromagnetic absorbing materials remains a challenge.In this work,Gd-Co ferrite@carbon core-shell structure composites were synthesized by a two-step hydrothermal method.The effects of rare earth Gd doping amount on the microstructure and electromagnetic wave absorption properties of cobalt ferrite@carbon composites were mainly studied.The results show that an appropriate amount of Gd doping can refine the crystal grain size of cobalt ferrite@carbon composites.However,when the doping amount of Gd exceeds the solid solubility threshold,the secondary phase GdFeO_(3)will be generated and the grain size will increase.When the doping amount of Gd is x=0.04,the reflection loss(RL) of the CoFe_(1.96)Gd_(0.04)O_(4)@C composites reaches the minimum value of -9.26 dB at the absorption layer thickness of 2.0 mm and a frequency of 13.67 GHz,and the effective absorption band(EAB) is 5.01 GHz(10.95-15.96 GHz).Compared with the CoFe_(2)O_(4)@C composites,the RL of the CoFe_(1.96)Gd_(0.04)O_(4)@C composites is increased by 79.35%,and the EAB is broadened by 3.51%.Gd ions enhance the dielectric loss through the grain size effect,and the increase of magnetocrystalline anisotropy enhances the magnetic loss.The CoFe_(1.96)Gd_(0.04)O_(4)@C composites have excellent impedance matching,which relies on the strong magnetic loss of ferrite,the interface polarization,and dipole polarization formed by the carbon shell to attenuate electromagnetic waves.
文摘利用恒电位仪、等离子发射光谱仪、电子能谱仪、X射线衍射仪、透射电子显微镜等考察和分析了引入稀土金属La时化学镀Co Fe B合金的阴极极化曲线、沉积速度、化学成分和晶体结构。结果表明 ,稀土La的介入明显改善了化学镀Co Fe B合金的静止电位和极化度 ,随镀液里稀土金属La添加量的增加 ,合金的沉积速度和镀层中La的含量都是先增后降 ,且都在La加入 0 6g·L- 1 时达到最大值。稀土La的介入使化学镀Co Fe B La合金镀层中B的含量减少 ,Co和Fe的含量增加 ,并使具有非晶态结构的化学镀Co Fe B合金转化为晶态结构的化学镀Co Fe B La合金。
文摘利用等离子发射光谱仪、电子能谱仪、X 射线衍射仪、透射电子显微镜等 ,考察引入稀土金属Ce后化学镀Co Fe B合金镀层的化学成分和晶体结构。结果表明 ,随镀液中稀土金属Ce添加量的增加 ,镀层中Ce的含量先增后降 ,在Ce =1 0g/L时达到最大值。Ce的介入使化学镀Co Fe B Ce合金镀层中B含量减少 ,Co和Fe含量增加 ,并使非晶态结构的合金镀层转化为微晶态结构。
文摘利用等离子发射光谱仪、电子能谱仪、X射线衍射仪、透射电子显微镜和显微硬度计等考察和分析了引入超声波和稀土金属铈时化学镀Co Ni B合金镀液的沉积速度、Co Ni B合金镀层的化学成分、晶体结构和显微硬度。结果表明 ,超声波和稀土金属铈的介入明显提高了化学镀Co Ni B合金的沉积速度 ,超声波的介入则提高了化学镀Co Ni B Ce合金镀层中稀土铈的含量。在超声波和稀土铈的共同作用下 ,化学镀Co Ni B合金镀层的化学组成发生了改变 ,镀层结构由非晶态向微晶和晶态转化 。
文摘利用恒电位仪、等离子发射光谱仪、电子能谱仪、X射线衍射仪、透射电子显微镜等研究了在常态和磁场条件下化学镀Co Ni B Ce合金的电化学性质、化学组成和组织结构。结果表明 ,微量稀土和磁场的介入改善了化学镀Co Ni B合金的静止电位和极化度 ;随镀液里稀土金属Ce量的增加 ,化学镀Co Ni B Ce合金镀层中的Ce含量是先增加后下降 ,均在Ce的质量浓度为 0 8g/L时达到最大值。在磁场和稀土铈的作用下 ,化学镀Co Ni B Ce合金镀层中B的含量减少 ,Co和Ni的含量增加 ,因而在常态下非晶态的Co Ni B镀层转变成了微晶结构的Co Ni B Ce镀层 ,在磁场条件下含稀土Ce的镀层则发生了晶化转变。
文摘借助等离子发射光谱、电子能谱仪、X 射线衍射仪、显微硬度计、磨损试验机和振动样品磁强计等分析了超声波对化学沉积Co Fe B Ce合金涂层化学成分、晶体结构、显微硬度、磨损体积和磁性能的影响。结果表明 ,在超声波的作用下 ,化学沉积Co Fe B Ce合金涂层中Co和Ce含量提高 ,Fe和B的含量则降低 ,而且具有微晶结构的化学沉积Co Fe B Ce合金涂层转变成了晶态结构的涂层。超声波的空化作用还明显地提高了化学沉积Co Fe B Ce合金涂层的显微硬度、耐磨性、饱和磁化强度与磁导率 ,降低了涂层的矫顽力 ,改善了涂层的软磁性能。
文摘Phase equilibria of the R-Fe-Co pseudoternary system with R≤33.3%(mole fraction, R=Sm 0.5Dy 0.5) were determined in an isothermal section at 1 073 K and a vertical section of RFe 2-RCo 2 by using OM, X-ray diffractometer, EPMA DTA techniques. There are seven intermetallic phases: (Sm, Dy)(Fe, Co) 2, (Sm, Dy)(Fe, Co) 3, (Sm, Dy) 6(Fe, Co) 23, (Sm, Dy) 2(Fe, Co) 7, (Sm, Dy)(Fe, Co) 5, Th 2Ni 17-type and Th 2Zn 17-type (Sm, Dy) 2(Fe, Co) 17. The (Sm, Dy) 6(Fe, Co) 23 phase dissolves 36% Co(mole fraction) at 1 073 K. However, the (Sm, Dy) 2(Fe, Co) 7 phase in R 2(Fe 1-xCo x) 7 alloys dissolves about 19% Fe(mole fraction) at 1 073 K.
