Medium-range order and crystallization in amorphous Al-Ni-Pr alloys

作者：Zhou JK^*; Bian XF; Wang WM; Xue XY; Wang SH; Zhao Y; Yin KB

来源：Materials Letters, 2004, 58(20): 2559-2563.

DOI：10.1016/j.matlet.2004.03.022

• medium-range order
• crystallization
• amorphous Al-Ni-Pr alloys

The amorphous structures of Al-Ni-Pr alloys with different compositions have been studied by X-ray diffraction (XRD). A distinct prepeak which characterizes the medium-range order (MRO) occurs at values of scattering vector Q = 10 - 20 nm(-1) in the structure factors of the amorphous alloys. The position of the prepeak shifts to smaller Q values as the concentration of Pr increases. The structure unit size increases with increasing Pr concentration. The addition of Pr can improve the interaction between unlike atoms. The crystallization behavior of Al-Ni-Pr alloys has been investigated by XRD, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) techniques. Depending on composition, Al-Ni-Pr amorphous alloys devitrify by either primary crystallization of pure, nanometer-sized fcc-Al phase or by the simultaneous precipitation of fcc-Al and intermetallic compounds. The prepeak in the structure factor is related to the strong chemical bonds that cause the intermetallic compounds (Al3Ni, AlPr) formation.

• 出版日期2004-8
• 单位山东大学