电流密度对Ni-Fe纳米合金微观结构及性能的影响

Effects of Current Intensity on Microstructure and Mechanical Properties of Bulk nano-crystalline Ni-Fe Alloy

通过电沉积制取大块Ni-Fe纳米合金,利用XRD、TEM、SEM等研究了Ni-Fe纳米合金(平均晶粒尺寸约20nm)的微观结构和变形机制,用单向拉伸试验机(MTS810)测试单向拉伸性能,表明这种合金的抗拉强度近2GPa,伸长率可达10.9%。Ni-Fe纳米合金对应变速率敏感较小,塑性变形导致了合金的晶粒长大,同时变形孪生和位错运动也起到一定作用。试验结果表明,纳米合金的塑性变形受晶界活动的影响。

Microstructure and deformation mechanism of nano-crystalline Ni-Fe bulk alloy with 20 nm in average diameter which was prepared by electrodeposition were investigated by XRD(X-ray diffraction),TEM(transmission electron microscope)and SEM(scanning electron microscope).Meanwhile,uniaxial tensile testing by the MTS810 reveal that the alloy exhibits 2 GPa in strength and 8%～10% in strain,respectively.The nano-crystalline Ni-Fe alloy exhibits somewhat sensitive for strain rate,and grain growth in the alloy is controlled by plastic deformation mechanism,in addition,deformation twinning and dislocation movement have some effects on the grain growth also.In addition,abnormal growth of grain in the Ni-Fe alloy can be observed.It is found that plastic deformation of the nano-crystalline is related to the grain boundary activities.