The magnetostrictive properties of <112> axial aligned Tb0.3Dy0.7(Fe1-xMx)1.95(M=Mn, Al, x=0～ 0.15) alloys prepared by directional solidification are reported. The influence of heat treatment on microstructure ...The magnetostrictive properties of <112> axial aligned Tb0.3Dy0.7(Fe1-xMx)1.95(M=Mn, Al, x=0～ 0.15) alloys prepared by directional solidification are reported. The influence of heat treatment on microstructure and the compressive stress effect of magnetostriction is discussed.展开更多
It is known to all, the spilling of pipeline may cause serious problems, especially when the pipe conveying petroleum, natural gas or other toxic substance. There are countless accidents during past century. Once the ...It is known to all, the spilling of pipeline may cause serious problems, especially when the pipe conveying petroleum, natural gas or other toxic substance. There are countless accidents during past century. Once the spilling occurs, the vibration of the pipe would aggravate spill situation and even result in crack of the pipe. The consequence will be more severe when the fluid inside is compressible. To prevent the detriment of the spilling model is developed by assuming the leakages as orifices or nozzles and a 2-D vertical simply supported pipe is selected to analyze the phenomena of the oscillation. Combining these two models, the oscillation model for the pipe with leakage is set up and the spilling effect is analyzed by numerical method. The amplitude of the pipe oscillation and the normal stress enlarge as the internal velocity increased, while the shear stress changes very little.展开更多
Micro parts are more difficult to be formed than macro parts because of size effects. The size effects on the flow stress of copper alloy C3602 with different lubricants were studied. Specimens were heat treated at 35...Micro parts are more difficult to be formed than macro parts because of size effects. The size effects on the flow stress of copper alloy C3602 with different lubricants were studied. Specimens were heat treated at 350℃ for 1 h and 700℃ for 3 h in nitrogen atmosphere, respectively. The initial diameters of the specimens were varied from 5 to 1 mm with a height-to-diameter ratio h0/D0 = 1.5. Cylinder compression was carried out in the lubrication condition with talc powder, without lubricant, with petroleum jelly, and with vegetable oil. The experiment was carried out at room temperature on a universal testing machine INSTRON 5569 with a strain rate of ε = 0.0025 A. The results show that with the same lubricant, the yield strength decreases with a decrease in specimen size for the specimens annealed at 350℃ for 1 b; however, it increases with a decrease in specimen size for the specimens annealed at 700℃ for 3 h. The yield strength decreases with an increase in grain size. The influences of lubricants on yield strength become larger with miniaturization of the specimens.展开更多
Polymer matrix RE-Fe giant magnetostrictire composite （GMPC） was prepared using bonding and magnetic field forming technique, and magnetostriction of samples was measured for different compressive stress. The experi...Polymer matrix RE-Fe giant magnetostrictire composite （GMPC） was prepared using bonding and magnetic field forming technique, and magnetostriction of samples was measured for different compressive stress. The experimental results show thai there is certain compressive effect in GMPC. And the influence of compressive stress on magnetostriction of sample was investigated. It offers essential reference for application and device design of GMPC.展开更多
The effect of the deformation condition on the axial compressive precision forming process of tube with curling die was investigated by using a rigid-plastic FEM. The results show that the forming accuracy depends mai...The effect of the deformation condition on the axial compressive precision forming process of tube with curling die was investigated by using a rigid-plastic FEM. The results show that the forming accuracy depends mainly on geometric condition rp/d0, little on tube material properties and friction condition; the relative gap △/2rp of double-walled tubes obtained decreases with Increasing rp/d0, and there is a parameter k for a given to/do or rp/t0, when rp/d0 >k, △/2rp< 1, otherwise △/2rp>1.展开更多
文摘The magnetostrictive properties of <112> axial aligned Tb0.3Dy0.7(Fe1-xMx)1.95(M=Mn, Al, x=0～ 0.15) alloys prepared by directional solidification are reported. The influence of heat treatment on microstructure and the compressive stress effect of magnetostriction is discussed.
基金the support of Thousand Talents Programthe National Natural Science Foundation of China(51479114)special fund for Marine Renewable Energy Project(GHME2014ZC01)
文摘It is known to all, the spilling of pipeline may cause serious problems, especially when the pipe conveying petroleum, natural gas or other toxic substance. There are countless accidents during past century. Once the spilling occurs, the vibration of the pipe would aggravate spill situation and even result in crack of the pipe. The consequence will be more severe when the fluid inside is compressible. To prevent the detriment of the spilling model is developed by assuming the leakages as orifices or nozzles and a 2-D vertical simply supported pipe is selected to analyze the phenomena of the oscillation. Combining these two models, the oscillation model for the pipe with leakage is set up and the spilling effect is analyzed by numerical method. The amplitude of the pipe oscillation and the normal stress enlarge as the internal velocity increased, while the shear stress changes very little.
基金supported by the National High-Tech Research and Development Program of China (No. 2006AA04Z316)Heilongjiang Natural Science Funds for Distinguished Young Scholars (No. JC-05-11)
文摘Micro parts are more difficult to be formed than macro parts because of size effects. The size effects on the flow stress of copper alloy C3602 with different lubricants were studied. Specimens were heat treated at 350℃ for 1 h and 700℃ for 3 h in nitrogen atmosphere, respectively. The initial diameters of the specimens were varied from 5 to 1 mm with a height-to-diameter ratio h0/D0 = 1.5. Cylinder compression was carried out in the lubrication condition with talc powder, without lubricant, with petroleum jelly, and with vegetable oil. The experiment was carried out at room temperature on a universal testing machine INSTRON 5569 with a strain rate of ε = 0.0025 A. The results show that with the same lubricant, the yield strength decreases with a decrease in specimen size for the specimens annealed at 350℃ for 1 b; however, it increases with a decrease in specimen size for the specimens annealed at 700℃ for 3 h. The yield strength decreases with an increase in grain size. The influences of lubricants on yield strength become larger with miniaturization of the specimens.
文摘Polymer matrix RE-Fe giant magnetostrictire composite （GMPC） was prepared using bonding and magnetic field forming technique, and magnetostriction of samples was measured for different compressive stress. The experimental results show thai there is certain compressive effect in GMPC. And the influence of compressive stress on magnetostriction of sample was investigated. It offers essential reference for application and device design of GMPC.
基金The authors would like to thank NSFC for support toenable the performing of this research (No. 59775055).
文摘The effect of the deformation condition on the axial compressive precision forming process of tube with curling die was investigated by using a rigid-plastic FEM. The results show that the forming accuracy depends mainly on geometric condition rp/d0, little on tube material properties and friction condition; the relative gap △/2rp of double-walled tubes obtained decreases with Increasing rp/d0, and there is a parameter k for a given to/do or rp/t0, when rp/d0 >k, △/2rp< 1, otherwise △/2rp>1.
