It is significant to investigate the action of nitrogen getters,which are used to synthesize type-IIa large diamond single crystals under high pressure and high temperature(HPHT).The reaction mechanism of Al as a nitr...It is significant to investigate the action of nitrogen getters,which are used to synthesize type-IIa large diamond single crystals under high pressure and high temperature(HPHT).The reaction mechanism of Al as a nitrogen getter and N in the HPHT alloy solvent is still indeterminate at present.In order to investigate the reaction of Al and N in the HPHT alloy solvent,Al and AlN are respectively added to the system of Fe55Ni29Co16−C(wt%,abbr.FeNiCo-C)for the synthesis of diamonds at about 5.5 GPa and 1600 K.The concentration of nitrogen in the diamonds is characterized by a micro Fourier transform infrared(micro-FTIR)spectrometer.The experimental results show that cN decreases when Al is added to the FeNiCo-C system.However,it increases when AlN is added.A reversible reaction confirms that Al and N can react and form AlN,simultaneously AlN can be decomposed into Al and N in the HPHT alloy solvent.Therefore the mechanism of eliminating the nitrogen of nitrogen getter Al is realized in detail.展开更多
It has been proved that the maximum magnetic energy product(BH)maxof hot-deformed Nd-Fe-B magnets can be effectively improved by adding substances with either high melting point or high saturation magnetization.In thi...It has been proved that the maximum magnetic energy product(BH)maxof hot-deformed Nd-Fe-B magnets can be effectively improved by adding substances with either high melting point or high saturation magnetization.In this work,we selected a ferromagnetic nano Fe_(55)Ni_(28)Co_(17) alloy powders with both high melting point and high saturation magnetization as the dopant to improve the(BH)max.By the addition of 1 wt% FeNiCo,the remanence increases by over 5%(from 1.36 to 1.44 T),resulting in a significant enhancement of(BH)maxfrom 355 to 396 kJ/m^(3)(from 44.6 to 49.7 MGOe).Microstructure observations reveal that the texture of grain alignment is improved,the concentrations of ferro magnetic elements(Fe,Ni,and Co) in the main phase and intergranular phase are increased so that the magnetization behavior of hot-deformed magnet changes(more easily shows reversible magnetization behaviors),which are the reasons why the high maximum energy product of hot-deformed magnet,is obtained.展开更多
基金by the National Natural Science Foundation of China under Grant No 50572032the Doctor Foundation of Henan Polytechnic University(648438).
文摘It is significant to investigate the action of nitrogen getters,which are used to synthesize type-IIa large diamond single crystals under high pressure and high temperature(HPHT).The reaction mechanism of Al as a nitrogen getter and N in the HPHT alloy solvent is still indeterminate at present.In order to investigate the reaction of Al and N in the HPHT alloy solvent,Al and AlN are respectively added to the system of Fe55Ni29Co16−C(wt%,abbr.FeNiCo-C)for the synthesis of diamonds at about 5.5 GPa and 1600 K.The concentration of nitrogen in the diamonds is characterized by a micro Fourier transform infrared(micro-FTIR)spectrometer.The experimental results show that cN decreases when Al is added to the FeNiCo-C system.However,it increases when AlN is added.A reversible reaction confirms that Al and N can react and form AlN,simultaneously AlN can be decomposed into Al and N in the HPHT alloy solvent.Therefore the mechanism of eliminating the nitrogen of nitrogen getter Al is realized in detail.
基金Project supported by the Zhejiang Province Technology Application Research Project (LGG19E010001)the Zhejiang Province Postdoctoral Science Foundation (ZJ2021080)the Key Research Program of the Chinese Academy of Sciences (ZDRW-CN2021-3)。
文摘It has been proved that the maximum magnetic energy product(BH)maxof hot-deformed Nd-Fe-B magnets can be effectively improved by adding substances with either high melting point or high saturation magnetization.In this work,we selected a ferromagnetic nano Fe_(55)Ni_(28)Co_(17) alloy powders with both high melting point and high saturation magnetization as the dopant to improve the(BH)max.By the addition of 1 wt% FeNiCo,the remanence increases by over 5%(from 1.36 to 1.44 T),resulting in a significant enhancement of(BH)maxfrom 355 to 396 kJ/m^(3)(from 44.6 to 49.7 MGOe).Microstructure observations reveal that the texture of grain alignment is improved,the concentrations of ferro magnetic elements(Fe,Ni,and Co) in the main phase and intergranular phase are increased so that the magnetization behavior of hot-deformed magnet changes(more easily shows reversible magnetization behaviors),which are the reasons why the high maximum energy product of hot-deformed magnet,is obtained.
