【摘要】 采用行星式高能球磨机,通过在室温下球磨纯元素混合粉末制备出Ni7Zr2非晶合金粉末.应用X射线衍射(XRD)、差热分析(DTA)和扫描电子显微镜(SEM)对不同球磨时间的混合粉末进行了研究.结果发现球磨时间对混合粉末的结构及颗粒形貌均存在显著影响.随着球磨时间的增加,Ni、Zr颗粒发生严重塑性变形,并且通过冷焊团聚起来,形成具有层状结构的复合颗粒.由于磨球的剧烈撞击,使得结构发生了严重的畸变,从而破坏了原有的有序结构而形成了无序结构.另外,在进一步球磨过程中,合金的晶粒不断减小,形成高体积分数的晶界,而金属粉末不断地发生塑性变形,形成了点缺陷、位错等高密度缺陷,晶格发生严重的畸变,晶体自由能也相应不断上升,最后产生了非晶转变.磁性能测量表明,该合金粉末具有较好的软磁性能.更多还原

【Abstract】 The powder of amorphous alloy Ni₇Zr₂ was synthesized by using high-power planetary ball-milling of the powder of pure elements at room temperature.The mixed alloy powder milled for different MA time was investigated by means of X-ray diffraction（XRD）,differential thermal analysis（DTA） and scanning electron microscopy（SEM）.The results showed that the milling time had significant influence on the powder structure and particle configuration.As the MA time increased,sever plastic deformation took place with the particles of Ni and Zr powder agglomerated by cold-welding and taking shape composite particles with lamellar structure.Because of sever impact during the process of ball-milling,the particle configuration of Ni and Zr powder was seriously distorted,making original orderly configuration to disorderly one.In addition,the average grain size of alloy powder decreased continuously during further ball-milling,volume fraction of grain interface became high.Ball-milling led to an increase in defect density such as spot defect and staggered defect,sever distortion of crystal cattice,increase of free energy in elements Zr and Ni,and finally,the alloy powder transformed into amorphous state.The result of VSM indicated that Ni₇Zr₂ amorphous alloy powder exhibited excellent soft magnetic properties.更多还原