The microstructure of ripening processed Cu-15%Cr alloys and deformed samples were examined under a 12T high magnetic field.The high magnetic field has accelerated the Ostwald Ripening process of Cr phase,the Cr-rich particles in 12T HMF case are coarser compared with 0T case.The 12T high magnetic field increased the peak strength of Cu(111)crystal plane and Cr(110)crystal plane,and appeared to has an orientation effect.Compared with the 0T case, the 12T high magnetic field case decreased the tensile strength and hardness.
WANG Wen-binWANG En-gangZHANG LinZUO Xiao-weiHE Ji-cheng
The effect of rotary electromagnetic stirring(EMS)on the Cu grain size and Fe dendrites is investigated in this paper,in order to get a Cu-Fe alloy ingot with good quality.The macro-and micro-structures are observed by Leica-DMR optical microscope.The solidification structures of Cu-2 and 8wt.%Fe consist with finer equiaxed grains. The Cu grain size is most sensitive to the Fe content.EMS can't effectively improve the grain size for the Cu-Fe alloy. For ingot cooled without EMS,there are also many large Fe-rich particles distribute in the Cu-matrix,beside the Fe dendrites,because of the existence of metastable miscibility gap in the undercooled liquid state.And the Fe-rich phases are not found in the ingots with EMS,indicating the EMS can affect the undercooling of the liquid and further restrain the liquid phase separation.Under the EMS,the Fe dendrites break up into many smaller Fe fragments.And the size of Fe fragments decreases with the increasing stirring current.
