采用双合金法制备Nd Dy Sn Fe Nb B永磁体,并对其磁性能、温度稳定性和显微组织进行了研究.研究结果表明∶Nd Dy Sn Fe Nb B磁体的内禀矫顽力Hci随Dy2O3含量的增加而增大,当Dy2O3含量为2%时,磁体的Hci和(BH)max较高,添加2%Dy2O3和0.3%Sn...采用双合金法制备Nd Dy Sn Fe Nb B永磁体,并对其磁性能、温度稳定性和显微组织进行了研究.研究结果表明∶Nd Dy Sn Fe Nb B磁体的内禀矫顽力Hci随Dy2O3含量的增加而增大,当Dy2O3含量为2%时,磁体的Hci和(BH)max较高,添加2%Dy2O3和0.3%Sn时,磁体的Br和(BH)max降低,而Hci可由656.0kA/m升高到1024.0kA/m,同时磁体的温度稳定性加强,磁通不可逆损失降低;当测量温度从20℃增加到160℃时,hirr为-2.3%,温度系数α为0.014%/℃.展开更多
The magnetic properties,microstructure and magnetic hardening of sintered (Nd_(1-x)Dy_x)_(16)Fe_(77.2)B_(6.8) and Nd_(16)Fe_(77.2)B_(6.8)+ywt-%Dy_2O_3 magnets have been stud- ied.As an addition of Dy to the magnet dur...The magnetic properties,microstructure and magnetic hardening of sintered (Nd_(1-x)Dy_x)_(16)Fe_(77.2)B_(6.8) and Nd_(16)Fe_(77.2)B_(6.8)+ywt-%Dy_2O_3 magnets have been stud- ied.As an addition of Dy to the magnet during smelting,Dy atoms may enter the matrix phase Nd_2Fe_(14)B,so as to enhance H_A,refine grains and improve boundary struc- ture,as well as to increase H_(ci)of the magnet.If Dy_2O_3 is added to powder material prior to sintering,Dy atoms diffuse into the epitaxial layer of grains of matrix phase causing enhancement of K′_1,also refinement of grains and improvement of boundary structure.The NdFeB based permanent magnets with higher H_(ci) and greater(BH)_m may be produced by adding about 2—3 wt-% Dy_2O_3 which make a favourable condition for lower cost.展开更多
Herein, the present paper were attempted to identify ions in LiF-DyF_3 melts according to the law of decreasing primary crystallization temperature and model analysis. Specifically.the primary crystallization temperat...Herein, the present paper were attempted to identify ions in LiF-DyF_3 melts according to the law of decreasing primary crystallization temperature and model analysis. Specifically.the primary crystallization temperatures of LiF-DyF_3 and LiF-DyF_3-Dy_2O_3 melts with various DyF_3 and Dy_2O_3 contents were determined by differential scanning calorimetry(DSC), and reactions occurring in the above melts were investigated using ideal dilute solution(Temkin and Flood) models. Moreover, crystal phases produced by rapid solidification of LiF-DyF_3, LiF-Dy_2O_3, DyF_3-Dy_2O_3, and LiF-DyF_3-Dy_2O_3 melts were identified by X-ray diffraction(XRD) analysis. The primary crystallization temperature of LiF-DyF_3 melts exhibits an approximately linear decrease with increasing molar fraction of DyF_3, and the general formula of complex ions in these melts is expressed as DyF_x^((3-x)),e.g., DyF_4^-. Finally, we investigated the dissolution of Dy_2O_3 in LiF-DyF_3 melts, showing that it was chemical in nature and afforded Dy_(1+x)O_(3x)F_(3-3x) and DyOF.展开更多
Developing a biomaterial for wound healing applications is still a challenge.Herein,dysprosium oxide(Dy_(2)O_(3)),aluminum oxide(Al_(2)O_(3)),and graphene oxide(GO)were embedded in cast films based on polycaprolactone...Developing a biomaterial for wound healing applications is still a challenge.Herein,dysprosium oxide(Dy_(2)O_(3)),aluminum oxide(Al_(2)O_(3)),and graphene oxide(GO)were embedded in cast films based on polycaprolactone(PCL)to be examined for wound dressing usage.Different techniques were used to characterize the fabricated films including X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),Raman,and scanning electron microscopy(SEM),besides their biological activity.The thermogravimetric analysis(TGA)exhibits high thermal stability as the scaffold weight decreases slightly to 98.6%after raising the temperature from room temperature to 280℃.The cell viability was investigated and it is shown that the viable cells grow up to approximately 93%at 75μg/mL.Meanwhile,the cell attachment shows excellent behavior as the cells attach on most of the surface of the modified PCL which shows high biocompatibility.展开更多
文摘采用双合金法制备Nd Dy Sn Fe Nb B永磁体,并对其磁性能、温度稳定性和显微组织进行了研究.研究结果表明∶Nd Dy Sn Fe Nb B磁体的内禀矫顽力Hci随Dy2O3含量的增加而增大,当Dy2O3含量为2%时,磁体的Hci和(BH)max较高,添加2%Dy2O3和0.3%Sn时,磁体的Br和(BH)max降低,而Hci可由656.0kA/m升高到1024.0kA/m,同时磁体的温度稳定性加强,磁通不可逆损失降低;当测量温度从20℃增加到160℃时,hirr为-2.3%,温度系数α为0.014%/℃.
文摘The magnetic properties,microstructure and magnetic hardening of sintered (Nd_(1-x)Dy_x)_(16)Fe_(77.2)B_(6.8) and Nd_(16)Fe_(77.2)B_(6.8)+ywt-%Dy_2O_3 magnets have been stud- ied.As an addition of Dy to the magnet during smelting,Dy atoms may enter the matrix phase Nd_2Fe_(14)B,so as to enhance H_A,refine grains and improve boundary struc- ture,as well as to increase H_(ci)of the magnet.If Dy_2O_3 is added to powder material prior to sintering,Dy atoms diffuse into the epitaxial layer of grains of matrix phase causing enhancement of K′_1,also refinement of grains and improvement of boundary structure.The NdFeB based permanent magnets with higher H_(ci) and greater(BH)_m may be produced by adding about 2—3 wt-% Dy_2O_3 which make a favourable condition for lower cost.
基金Project supported by the National Natural Science Foundation of China(5167041092,51564015)Natural Science Foundation of Jiangxi Province(20161BAB206142)Outstanding Doctoral Dissertation Project Fund of JXUST(YB2017007)
文摘Herein, the present paper were attempted to identify ions in LiF-DyF_3 melts according to the law of decreasing primary crystallization temperature and model analysis. Specifically.the primary crystallization temperatures of LiF-DyF_3 and LiF-DyF_3-Dy_2O_3 melts with various DyF_3 and Dy_2O_3 contents were determined by differential scanning calorimetry(DSC), and reactions occurring in the above melts were investigated using ideal dilute solution(Temkin and Flood) models. Moreover, crystal phases produced by rapid solidification of LiF-DyF_3, LiF-Dy_2O_3, DyF_3-Dy_2O_3, and LiF-DyF_3-Dy_2O_3 melts were identified by X-ray diffraction(XRD) analysis. The primary crystallization temperature of LiF-DyF_3 melts exhibits an approximately linear decrease with increasing molar fraction of DyF_3, and the general formula of complex ions in these melts is expressed as DyF_x^((3-x)),e.g., DyF_4^-. Finally, we investigated the dissolution of Dy_2O_3 in LiF-DyF_3 melts, showing that it was chemical in nature and afforded Dy_(1+x)O_(3x)F_(3-3x) and DyOF.
基金funded by the Scientific Research Deanship at University of Ha'il,Saudi Arabia through project number RG-20-222。
文摘Developing a biomaterial for wound healing applications is still a challenge.Herein,dysprosium oxide(Dy_(2)O_(3)),aluminum oxide(Al_(2)O_(3)),and graphene oxide(GO)were embedded in cast films based on polycaprolactone(PCL)to be examined for wound dressing usage.Different techniques were used to characterize the fabricated films including X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),Raman,and scanning electron microscopy(SEM),besides their biological activity.The thermogravimetric analysis(TGA)exhibits high thermal stability as the scaffold weight decreases slightly to 98.6%after raising the temperature from room temperature to 280℃.The cell viability was investigated and it is shown that the viable cells grow up to approximately 93%at 75μg/mL.Meanwhile,the cell attachment shows excellent behavior as the cells attach on most of the surface of the modified PCL which shows high biocompatibility.
