The glass-forming ability and properties of Ni-based Ni-Fe-B-Si-Ta bulk metallic glasses are explored in this work. The alloy compositions are determined by using a combination of the cluster line approach, the multi-...The glass-forming ability and properties of Ni-based Ni-Fe-B-Si-Ta bulk metallic glasses are explored in this work. The alloy compositions are determined by using a combination of the cluster line approach, the multi-alloying strategy and the substitutions of similar elements. Bulk metallic glasses with diameters of 3 mm take shape at compositions formulated under the clus- ter-plus-glue-atom model [M9B]B~[(Ni1-xFex)7.71(Si0.66Ta0.34)1.29B]B0.94=(Ni1-xFex)70.5B17.7Si7.8Ta4, x=0.35–0.45, where the bracketed part is the cluster and the unbracketed part is the glue atoms. These alloys exhibit good magnetic properties. The maximum Is is found in the (Ni0.55Fe0.45)70.5B17.7Si7.8Ta4 alloy which reaches 0.51 T, with its Hc as low as 8.5 A/m. Interestingly, these alloys display dual glass transitions at (Ni0.65Fe0.35)70.5B17.7Si7.8Ta4, (Ni0.60Fe0.4)70.5B17.7Si7.8Ta4 and (Ni0.55Fe0.45)70.5B17.7- Si7.8Ta4 as unveiled by Temperature-Modulated Differential Scanning Calorimetry.展开更多
As a potential ferromagnetic shape memory alloy, Ni-Co-Al has excellent mechanical properties, large ma gentic-field-induced strain and high martensitic transformation temperature. The relationship between microstruct...As a potential ferromagnetic shape memory alloy, Ni-Co-Al has excellent mechanical properties, large ma gentic-field-induced strain and high martensitic transformation temperature. The relationship between microstructure and performance （mechanical and magnetic properties） of Ni-Co-Al with different Co/Al atomic ratios （RCo/Al） was investigated. Samples exhibit β and γ dual-phase structure. The γ phase grows coarse and the volume fraction of γ phase increases with the rise of RCo/Al. Besides, sample with high amount of γ phase content has smaller βgrains ow- ing to the pinning effect of γ phase. The martensite, transformed from β phase, is tetragonal L10 structure with a （111） twinning plane. The martensitic transformation temperature of samples ascends with increasing R co/Al owing to more Co embedded into the cell, which makes the valence electron concentration （e/a） of system rise. The satura- tion magnetization （Ms） of samples increases as Rco/Al rises because Co-rich 7 phase has excellent magnetic property. Meanwhile, both compressive and micro-hardness tests reveal that the samples containing more γ phase have excel- lent ductility due to the intrinsic good ductility nature of γ phase.展开更多
Hydrogen is an important source of energy.The natural resouces of hydrogen is plenty and it gives us lots of heat, and it is dean. One of difficulties of developing hydrogen sources of energy is hydrogen storage. Hydr...Hydrogen is an important source of energy.The natural resouces of hydrogen is plenty and it gives us lots of heat, and it is dean. One of difficulties of developing hydrogen sources of energy is hydrogen storage. Hydrogen storage tank is either dangous or a little of capacity. Liquid hydrogen occupys small space. Liquefaction temperature of hydrogen is -253℃ and need better heat insulation protection, the volumn and weight of heat insulation layer are equal to hydrogen storage tank. Hydrogen storage utillizing hydrogen storage material is a very safety, economical and effective method. Hydrogen storage material is either a medium of sofid hydrogen storage or is negative pole active material of Ni-H battery,and is the one of key technoloy of fuel and Ni-H battery, it is an important material of new sources of energy too.Nanotechnology is introduced Mg-matrix hydrogen storage alloy and is achieved progress gteatly,but hydrogen storage alloy need be mode further improvment on applying investigation.展开更多
基金supported by the National Science Foundation of China (Grant Nos. 50631010 and 50901012)the National Basic Research Program of China (Grant Nos. 2007CB613902 and 2008CB617614)
文摘The glass-forming ability and properties of Ni-based Ni-Fe-B-Si-Ta bulk metallic glasses are explored in this work. The alloy compositions are determined by using a combination of the cluster line approach, the multi-alloying strategy and the substitutions of similar elements. Bulk metallic glasses with diameters of 3 mm take shape at compositions formulated under the clus- ter-plus-glue-atom model [M9B]B~[(Ni1-xFex)7.71(Si0.66Ta0.34)1.29B]B0.94=(Ni1-xFex)70.5B17.7Si7.8Ta4, x=0.35–0.45, where the bracketed part is the cluster and the unbracketed part is the glue atoms. These alloys exhibit good magnetic properties. The maximum Is is found in the (Ni0.55Fe0.45)70.5B17.7Si7.8Ta4 alloy which reaches 0.51 T, with its Hc as low as 8.5 A/m. Interestingly, these alloys display dual glass transitions at (Ni0.65Fe0.35)70.5B17.7Si7.8Ta4, (Ni0.60Fe0.4)70.5B17.7Si7.8Ta4 and (Ni0.55Fe0.45)70.5B17.7- Si7.8Ta4 as unveiled by Temperature-Modulated Differential Scanning Calorimetry.
文摘As a potential ferromagnetic shape memory alloy, Ni-Co-Al has excellent mechanical properties, large ma gentic-field-induced strain and high martensitic transformation temperature. The relationship between microstructure and performance （mechanical and magnetic properties） of Ni-Co-Al with different Co/Al atomic ratios （RCo/Al） was investigated. Samples exhibit β and γ dual-phase structure. The γ phase grows coarse and the volume fraction of γ phase increases with the rise of RCo/Al. Besides, sample with high amount of γ phase content has smaller βgrains ow- ing to the pinning effect of γ phase. The martensite, transformed from β phase, is tetragonal L10 structure with a （111） twinning plane. The martensitic transformation temperature of samples ascends with increasing R co/Al owing to more Co embedded into the cell, which makes the valence electron concentration （e/a） of system rise. The satura- tion magnetization （Ms） of samples increases as Rco/Al rises because Co-rich 7 phase has excellent magnetic property. Meanwhile, both compressive and micro-hardness tests reveal that the samples containing more γ phase have excel- lent ductility due to the intrinsic good ductility nature of γ phase.
文摘Hydrogen is an important source of energy.The natural resouces of hydrogen is plenty and it gives us lots of heat, and it is dean. One of difficulties of developing hydrogen sources of energy is hydrogen storage. Hydrogen storage tank is either dangous or a little of capacity. Liquid hydrogen occupys small space. Liquefaction temperature of hydrogen is -253℃ and need better heat insulation protection, the volumn and weight of heat insulation layer are equal to hydrogen storage tank. Hydrogen storage utillizing hydrogen storage material is a very safety, economical and effective method. Hydrogen storage material is either a medium of sofid hydrogen storage or is negative pole active material of Ni-H battery,and is the one of key technoloy of fuel and Ni-H battery, it is an important material of new sources of energy too.Nanotechnology is introduced Mg-matrix hydrogen storage alloy and is achieved progress gteatly,but hydrogen storage alloy need be mode further improvment on applying investigation.
