期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
Hydrogen absorption/desorption cycling performance of Mg-based alloys with in-situ formed Mg_(2)Ni and LaH_(x)(x=2,3)nanocrystallines 被引量:4
1
作者 Fenghai Guo tiebang zhang +1 位作者 Limin Shi Lin Song 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第4期1180-1192,共13页
Aiming to elucidate the hydrogen absorption/desorption cycling properties of Mg-based alloys with in-situ formed Mg_(2)Ni and LaH_(x)(x=2,3)nanocrystallines,the hydrogen storage cycle stability,hydriding/dehydriding c... Aiming to elucidate the hydrogen absorption/desorption cycling properties of Mg-based alloys with in-situ formed Mg_(2)Ni and LaH_(x)(x=2,3)nanocrystallines,the hydrogen storage cycle stability,hydriding/dehydriding cycling kinetics and thermodynamic stability of the experimental alloys have been investigated in detail.The results show that the Mg-Ni-La alloys exhibit improved hydrogen storage cycling properties and can remain storage hydrogen above 5.5 wt%after 200 cycles.With the increase of cycling numbers,the dehydrogenation rates of the experimental samples increase firstly and then gradually decrease,and eventually maintain relative stable state.Microstructure observation reveals that powders sintering and hydrogen decrepitation both exist during hydrogen absorption/desorption cycles due to repeated volume expansion and contraction.Meanwhile,the in-situ formed LaH_(x)(x=2,3)and Mg_(2)Ni nanocrystallines stabilize the microstructures of the particles and hinder the powders sintering.After 200 cycles,the average particle size of the experimental samples decreases and the specific surface area apparently increases,which leads to the decomposition temperatures of MgH_(2)and Mg_(2)NiH_(4)slightly shift to lower temperatures.Moreover,Mg_(2)Ni and LaH_(x)(x=2,3)have been proven to be stable catalysts during long-term cycling,which can still uniformly distribute within the powders after 200 cycles. 展开更多
关键词 Mg-based hydrogen storage alloys Cycle stability Microstructure evolution Catalyst stability THERMODYNAMICS
下载PDF
Catalytic performance of Zr-doped CuO-CeO2 oxides for CO selective oxidation in H2-rich stream 被引量:8
2
作者 Limin Shi Chuanlei Gao +2 位作者 Fenghai Guo Yujing Wang tiebang zhang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2019年第7期720-725,共6页
Zr-doped CuO-CeO2 catalysts for CO selective oxidation were designed and prepared by the hydrothermal method and coprecipitation. The experimental samples were characterized by means of N2 adsorption-desorption isothe... Zr-doped CuO-CeO2 catalysts for CO selective oxidation were designed and prepared by the hydrothermal method and coprecipitation. The experimental samples were characterized by means of N2 adsorption-desorption isotherms, powder X-ray diffraction, temperature-programmed reduction and Xray photoelectron spectroscopy. It is observed that the catalyst prepared by hydrothermal method exhibits larger specific surface area, smaller crystalline size and higher dispersion of active components compared with those of the catalyst obtained by coprecipitation. Meanwhile, redox properties of copper oxide are improved significantly and highly dispersed copper species providing CO oxidation sites are present on the surface. Furthermore, adsorptive centers of CO and active oxygen species increase on the copper-ceria interfaces. The Zr-doped CuO-CeO2 catalyst prepared by hydrothermal method possesses superior catalytic activity and selectivity for selective oxidation of CO at low temperature compared with those of the sample prepared by coprecipitation. The temperature corresponding to 50% CO conversion is only 73 ℃ and the temperature span of total CO conversion is expanded from 120 to 160 ℃. 展开更多
关键词 CATALYTIC performance CuO-CeO2 OXIDES ZR doping CO selective oxidation Hydrogen PURIFICATION RARE earths
原文传递
On the reversibility of the α_(2)/ω_(o) phase transformation in a high Nb containing TiAl alloy during high temperature deformation 被引量:1
3
作者 Lin Song Fritz Appel +6 位作者 Andreas Stark Uwe Lorenz Junyang He Zhanbing He Junpin Lin tiebang zhang Florian Pyczak 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第34期96-102,共7页
The transformations between the phasesα_(2)(Ti_(3)Al)andω_(o)were investigated in a lamellar multiphase titanium aluminide alloy based onγ(TiAl).The paper complements an earlier investigation performed on the same ... The transformations between the phasesα_(2)(Ti_(3)Al)andω_(o)were investigated in a lamellar multiphase titanium aluminide alloy based onγ(TiAl).The paper complements an earlier investigation performed on the same material in which the importance of deformation-induced twin structures for theα_(2)→ω_(o) transformation was demonstrated.The present study shows that the reverse transformationω_(o)→α_(2) can also occur during high-temperature deformation.The transformation is probably triggered by constraint stresses,which exist between the different constituents due to the crystalline mismatch.The combined operation of mechanical twinning of theα_(2) phase and the reversible transformation fully converts theα_(2) lamellae into a mixture ofα_(2) andω_(o).This conversion greatly reduces the mechanical anisotropy existing in formerα_(2) lamellae.Regarding the technical use of the alloy,the stability of the converted structure with respect to further annealing was also examined.The reported processes occur at the nano-meter and sub nano-meter scale,thus,advanced characterization techniques were applied,such as high-resolution transmission electron microscopy(HRTEM)and atom probe tomography(APT). 展开更多
关键词 TiAl alloys Phase transformation Electron microscopy MICROSTRUCTURE
原文传递
Deformation and phase transformation behaviors of a high Nb-containing TiAl alloy compressed at intermediate temperatures
4
作者 Xu Liu Lin Song +5 位作者 Andreas Stark Uwe Lorenz Zhanbing He Junpin Lin Florian Pyczak tiebang zhang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第7期89-96,共8页
In modernβ-solidified TiAl alloys,the decomposition of α_(2) phase is frequently observed during heat treatment or high-temperature deformation of the alloys.In this study,high-temperature deformation and decomposit... In modernβ-solidified TiAl alloys,the decomposition of α_(2) phase is frequently observed during heat treatment or high-temperature deformation of the alloys.In this study,high-temperature deformation and decomposition mechanisms of α_(2) phase in a Ti-45Al-8.5Nb-0.2B-0.2W-0.02Y alloy are investigated.In a sample deformed at 800℃,the precipitation ofβ_(o)(ω_(o))phase is observed within the equiaxed α_(2) phase.The nucleation ofω_(o) particles within theβ_(o) matrix indicates the α_(2)→β_(o)→ω_(o) transformation.In addition,numerous y phase precipitates form within theβ_(o)(ω)areas.The α_(2) lamellae decompose into ultrafine( α_(2)+γ)lamellae and coarsened y lamellae via α_(2)→ α_(2)+γand α_(2)→γtransformation,re-spectively.Moreover,theω_(o) phase nucleates within the ultrafine lamellae via α_(2)→ω_(o) transformation.However,in a sample deformed at 1000℃,the nucleation ofβ_(o) particles is sluggish,which is caused by the efficient release of the internal stress via dynamic recrystallization(DRX).These results indicate that complex phase transformations can be introduced by the decomposition of α_(2) phase in TiAl alloys with a high amount ofβ-stabilizing elements. 展开更多
关键词 TiAl alloys Phase transformation Microstructure Electron microscopy
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部