The reverse transformation behavior of TiNi alloy wires prestrained at different temperatures is studied in this paper. Experimental results show that prestrain at different temperatures obviously affects the reverse ...The reverse transformation behavior of TiNi alloy wires prestrained at different temperatures is studied in this paper. Experimental results show that prestrain at different temperatures obviously affects the reverse transformation behavior of the TiNi alloy wire. A single peak appears on the DSC curves of wires prestrained at 253-313K (in the martensite state). However deformed at 333K, three consecutive peaks appear on the DSC curves of wires with a smaller prestrain and a single peak appears on the DSC curves of the wires with a larger prestrain. The recovery strain ratio of the wires prestrained at 253-313K are very similar. However, the ratio of the wire predeformed at 333K is obviously smaller than that of the wire prestrained in the martensite state.展开更多
Effect of thermal annealing on the magnetization reversal behavior of α-Fe/Nd2Fe14B alloys was investigated. A drastic in- crease of the remanence Mr from 0.67 up to 0.87 T and remanence ratio Mr/Ms from 0.66 up to 0...Effect of thermal annealing on the magnetization reversal behavior of α-Fe/Nd2Fe14B alloys was investigated. A drastic in- crease of the remanence Mr from 0.67 up to 0.87 T and remanence ratio Mr/Ms from 0.66 up to 0.76, respectively, was observed in the α-Fe/NdEFel413 alloys annealed at 610 ℃ as compared with the as-quenched sample. Whereas the further annealing at 680 ℃ resulted in a strong increase of the corecivity Hc as high as 491 kA/m but a slight decrease in Mr. The analysis result of the magnetization re- versal behavior showed that the maximum value of the integrated recoil loop area about 1.58 kJ/m3 was obtained in the α-Fe/Nd2Fe14B alloys at the annealing temperature of 610℃, significantly lower than other annealed samples. This indicated a sig- nificant advantage for the application of this material as permanent magnets in electrical machines and generators due to a low energy loss.展开更多
Cr/SmCo/Cr films with different SmCo thickness were deposited on glass substrates by magnetron sputtering,followed by an annealing process at 550 °C for 20 min.Experimental results showed that the SmCo film of 30...Cr/SmCo/Cr films with different SmCo thickness were deposited on glass substrates by magnetron sputtering,followed by an annealing process at 550 °C for 20 min.Experimental results showed that the SmCo film of 30 nm exhibited two-phase behavior in the demagnetization process,the obvious kink was observed near zero.For the SmCo film of 50 nm,the kink was invisible,and a single phase like behavior was obtained in the demagnetization process.The reversal behavior became consistent in the thicker films.Moreover,the coercivity reduced and the saturated magnetization increased obviously with the increasing thickness.X-ray diffraction results indicated that the average grain size of SmCo 5 in the thicker films were almost 30 nm,but the quantity of SmCo 5 grains increased with the increasing thickness,which enhanced the intergrain exchange coupling（IEC） of the SmCo 5 hard phases.The increase of IEC improved the magnetic properties of SmCo films with increasing thickness.展开更多
基金This work is funded by the National Natural Science Foundation the Peoples Republic of China (No. 50071037)
文摘The reverse transformation behavior of TiNi alloy wires prestrained at different temperatures is studied in this paper. Experimental results show that prestrain at different temperatures obviously affects the reverse transformation behavior of the TiNi alloy wire. A single peak appears on the DSC curves of wires prestrained at 253-313K (in the martensite state). However deformed at 333K, three consecutive peaks appear on the DSC curves of wires with a smaller prestrain and a single peak appears on the DSC curves of the wires with a larger prestrain. The recovery strain ratio of the wires prestrained at 253-313K are very similar. However, the ratio of the wire predeformed at 333K is obviously smaller than that of the wire prestrained in the martensite state.
基金Foundation item： Project supported by Project of Zhejiang Province Innovative Research Team （2010R50016）, Zhejiang Provincial Natural Science Foundation （Y6100640）, National Natural Science Foundation of China （51001092, 51271172） and National Public Profession Sci- entific Research （201210107）
文摘Effect of thermal annealing on the magnetization reversal behavior of α-Fe/Nd2Fe14B alloys was investigated. A drastic in- crease of the remanence Mr from 0.67 up to 0.87 T and remanence ratio Mr/Ms from 0.66 up to 0.76, respectively, was observed in the α-Fe/NdEFel413 alloys annealed at 610 ℃ as compared with the as-quenched sample. Whereas the further annealing at 680 ℃ resulted in a strong increase of the corecivity Hc as high as 491 kA/m but a slight decrease in Mr. The analysis result of the magnetization re- versal behavior showed that the maximum value of the integrated recoil loop area about 1.58 kJ/m3 was obtained in the α-Fe/Nd2Fe14B alloys at the annealing temperature of 610℃, significantly lower than other annealed samples. This indicated a sig- nificant advantage for the application of this material as permanent magnets in electrical machines and generators due to a low energy loss.
基金Project supported by National Natural Science Foundation of China (50871014)New Teacher Foundation of Ministry of Education(200800081030)+1 种基金Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality (PHR201007122)Beijing Natural Science Foundation (2102014)
文摘Cr/SmCo/Cr films with different SmCo thickness were deposited on glass substrates by magnetron sputtering,followed by an annealing process at 550 °C for 20 min.Experimental results showed that the SmCo film of 30 nm exhibited two-phase behavior in the demagnetization process,the obvious kink was observed near zero.For the SmCo film of 50 nm,the kink was invisible,and a single phase like behavior was obtained in the demagnetization process.The reversal behavior became consistent in the thicker films.Moreover,the coercivity reduced and the saturated magnetization increased obviously with the increasing thickness.X-ray diffraction results indicated that the average grain size of SmCo 5 in the thicker films were almost 30 nm,but the quantity of SmCo 5 grains increased with the increasing thickness,which enhanced the intergrain exchange coupling（IEC） of the SmCo 5 hard phases.The increase of IEC improved the magnetic properties of SmCo films with increasing thickness.
