交变磁场对多晶纯铝位错密度及显微硬度的影响

Effect of Alternating Magnetic Field on Dislocation Density and Microhardness of Pure Polycrystalline Aluminum

研究了交变磁场对退火的形变多晶纯铝位错密度及显微硬度的影响。结果表明:在交变磁场中退火后纯铝试样的衍射峰半高宽(FWHM)及显微硬度增加,且半高宽及显微硬度随磁感应强度的增加而增加。交变磁场产生的磁压和位错芯膨胀效应对位错密度的影响很小。位错密度的变化主要归因于磁致塑性效应的作用,即:在交变磁场作用下,位错芯与障碍物之间的相互作用由低能态的单重态转变为高能态的三重态,位错更容易从钉扎处逃逸,促进位错运动。这一效应导致形变纯铝的XRD衍射峰变宽,位错密度增加,硬度提高。

Effect of the alternating magnetic field(AMF)on dislocation density and microhardness of deformed pure polycrystalline aluminum annealed were studied.The results showed that the full width at half maximum(FWHM)and microhardness of the pure aluminum samples annealed in the AMF increased,and both of them increased with the increase of magnetic induction in AMF.The magnetic pressure produced by AMF and dislocation core expansion effect had a little effect on dislocation density.The variation of dislocation density was mainly attributed to magnetoplastic effect,i.e.under the action of alternating magnetic field,the interaction between dislocation core and obstacle transformed from singlet state of low energy state to triplet state of high energy state,which promoted the dispinning of dislocations from obstacles and motion of dislocations.The magnetoplastic effect resulted in broader XRD diffraction peak,and increase in both dislocation density and icrohardness of the deformed pure aluminium.