The microstructure ofthe Mg/MmNi5-x (CoAlMn )x composite hydrogen storage material preparedby the method of mechanical alloyingwas characterized by X-ray diffraction, SEM and particle size distribution analysis. By me...The microstructure ofthe Mg/MmNi5-x (CoAlMn )x composite hydrogen storage material preparedby the method of mechanical alloyingwas characterized by X-ray diffraction, SEM and particle size distribution analysis. By measuring PCTcurves, the hydrogen absorption properties of the composite was evaluated.The results show that nanocrystallinecomposite structure can be obtainedunder adequate ball milling condition. The reactive activation and hydrogen absorption capacity are improved compared with the sole MmNi5-x(CoAlMn)x alloy. The effect ofmagnesium on the microstructure andhydrogen absorption properties of thecomposite were also evaluated.展开更多
The morphology and structure of melt spinning Ni-33.6at% Al doped with B and RE were investigated.The results show that the alloy consists of L10 martensitic grains and L12 Ni3Al at the grain boundaries when it contai...The morphology and structure of melt spinning Ni-33.6at% Al doped with B and RE were investigated.The results show that the alloy consists of L10 martensitic grains and L12 Ni3Al at the grain boundaries when it contains no B and RE.The addition of 0.11-0.31wt% B can suppress the martensitic transformation and Ni3Al separation at the boundaries,and a supersaturated B2 single phase NiAl is obtained.The addition of 0.05wt% RE can eliminate Ni3Al precipitated at the boundaries and get complete martensite,but 0.2-0.8wt% RE addition can suppress the martensitic transformation, and supersaturated B2 single phase NiAl is obtained.The formation mechanism of supersaturated B2 single phase NiAl has been analyzed.展开更多
By measuring and analyzing the crystallization activation energy (CAE) of Fe-based amorphous alloy Fe79B16Si5 and Fe78B13Si9, it is reconfirmed and further analyzed that the conventional Kissinger method does not conf...By measuring and analyzing the crystallization activation energy (CAE) of Fe-based amorphous alloy Fe79B16Si5 and Fe78B13Si9, it is reconfirmed and further analyzed that the conventional Kissinger method does not conform with the premise of Kissinger equation, namely, samples with different heating rates should keep a constant fraction of transformation at the exothermal peak temperature Tp of DSC thermogram. The XRD equal first peak height (EFPH) method is applied to CAE measurement of Fe-based amorphous alloy for the first time. It is shown again that the EFPH method coincides with the premise of Kissinger equation. The procedure of EFPH method is introduced in detail in this paper. The accuracy in determining CAE of amorphous alloy may be improved by applying the EFPH method. As a result, the mechanism of embrittlement of amorphous alloy may be better elucidated.展开更多
Diamond-like carbon(DLC) films with different thickness were deposited by filtered cathode vacuum arc(FCVA).Vis-Raman and spectroscopic ellipsometry were employed to analyze the structure of DLC films.The wavelength o...Diamond-like carbon(DLC) films with different thickness were deposited by filtered cathode vacuum arc(FCVA).Vis-Raman and spectroscopic ellipsometry were employed to analyze the structure of DLC films.The wavelength of Vis-Raman is 514.5 nm.Experimental results show that structures of DLC films are affected by film thicknesses.When the film thickness increases from 2 to 30 nm,the G-peak position(G-pos) shifts to higher wavelength,the intensity ratio ID/IG and the extinction coefficient Ks decrease.It is indicated that the content of sp3 bond increases with film thickness.However,when the film thickness increases from 30 nm to 50 nm,ID/IG and Ks increase.The content of sp3 bonds decreases with film thickness.展开更多
文摘The microstructure ofthe Mg/MmNi5-x (CoAlMn )x composite hydrogen storage material preparedby the method of mechanical alloyingwas characterized by X-ray diffraction, SEM and particle size distribution analysis. By measuring PCTcurves, the hydrogen absorption properties of the composite was evaluated.The results show that nanocrystallinecomposite structure can be obtainedunder adequate ball milling condition. The reactive activation and hydrogen absorption capacity are improved compared with the sole MmNi5-x(CoAlMn)x alloy. The effect ofmagnesium on the microstructure andhydrogen absorption properties of thecomposite were also evaluated.
文摘The morphology and structure of melt spinning Ni-33.6at% Al doped with B and RE were investigated.The results show that the alloy consists of L10 martensitic grains and L12 Ni3Al at the grain boundaries when it contains no B and RE.The addition of 0.11-0.31wt% B can suppress the martensitic transformation and Ni3Al separation at the boundaries,and a supersaturated B2 single phase NiAl is obtained.The addition of 0.05wt% RE can eliminate Ni3Al precipitated at the boundaries and get complete martensite,but 0.2-0.8wt% RE addition can suppress the martensitic transformation, and supersaturated B2 single phase NiAl is obtained.The formation mechanism of supersaturated B2 single phase NiAl has been analyzed.
文摘By measuring and analyzing the crystallization activation energy (CAE) of Fe-based amorphous alloy Fe79B16Si5 and Fe78B13Si9, it is reconfirmed and further analyzed that the conventional Kissinger method does not conform with the premise of Kissinger equation, namely, samples with different heating rates should keep a constant fraction of transformation at the exothermal peak temperature Tp of DSC thermogram. The XRD equal first peak height (EFPH) method is applied to CAE measurement of Fe-based amorphous alloy for the first time. It is shown again that the EFPH method coincides with the premise of Kissinger equation. The procedure of EFPH method is introduced in detail in this paper. The accuracy in determining CAE of amorphous alloy may be improved by applying the EFPH method. As a result, the mechanism of embrittlement of amorphous alloy may be better elucidated.
文摘Diamond-like carbon(DLC) films with different thickness were deposited by filtered cathode vacuum arc(FCVA).Vis-Raman and spectroscopic ellipsometry were employed to analyze the structure of DLC films.The wavelength of Vis-Raman is 514.5 nm.Experimental results show that structures of DLC films are affected by film thicknesses.When the film thickness increases from 2 to 30 nm,the G-peak position(G-pos) shifts to higher wavelength,the intensity ratio ID/IG and the extinction coefficient Ks decrease.It is indicated that the content of sp3 bond increases with film thickness.However,when the film thickness increases from 30 nm to 50 nm,ID/IG and Ks increase.The content of sp3 bonds decreases with film thickness.
