EBSD Study on the Effect of a Strong Axial Magnetic Field on the Microstructure and Crystallography of Al-Ni Alloys During Solidification

Xi Li,Yves Fautrelle,Rene Moreau,Xionggang Lu,Zhongming Ren,Annie Gagnoud,Dafan Du

doi:10.1007/s11661-015-3279-4

Abstract

The effect of a strong magnetic field on the microstructure and crystallography of the primary and eutectic Al3Ni phases in Al-Ni alloys was investigated by using EBSD. The results show that the magnetic field significantly affected the microstructures and crystallography during both volume and directional solidification. As a result, the Al3Ni primary phases were aligned with the 〈001〉 crystal direction along the magnetic field and formed a layer-like structure. The magnetic field intensity, solidification temperature, growth speed, and alloy composition played important roles during the alignment process of the Al3Ni primary phase. Indeed, the alignment degree increased with the magnetic field and the solidification temperature during normal solidification. Moreover, the effect of the magnetic field on the crystallography of the Al-Al3Ni eutectic in the Al-Ni alloys was also studied. The applied magnetic field modified the orientation of the preferred growth direction of the Al3Ni eutectic fiber and the crystallographic orientation relationship of the Al-Al3Ni eutectic. The orientation of the preferred growth direction of the Al3Ni eutectic fiber depended mainly on the solidification direction and the alignment of the Al3Ni primary phase. Furthermore, a method for controlling the crystallization process by adjusting the angle between the solidification direction and the magnetic field was proposed.

Highlights

DUE to the recent development of superconducting technology, a strong magnetic field with a relatively wide spatial extent has become easy to produce
The plane of the Al3Ni primary phase was perpendicular to the magnetic field direction when the magnetic field reached 1 T
Along with the alignment of the Al3Ni primary phase, the h001i crystal direction of the Al3Ni crystal was oriented along the magnetic field

Summary

Introduction

DUE to the recent development of superconducting technology, a strong magnetic field with a relatively wide spatial extent has become easy to produce. Rango[8] extended this investigation to the solidification of paramagnetic YBa2Cu3O7 material and obtained a texture crystal structure in a magnetic field. Katsuk[9] reported that diamagnetic benzophenone crystallized from n-hexane and KCl and that BaCl2 crystallized from a solution aligned in a magnetic field of 10 T. This alignment behavior has been investigated intensively.[10,11,12] Asai[10] observed perpendicular alignment in Al-Si-Fe alloy during solidification in a strong magnetic field. The textured crystal growth of Bi-2201[11] and Bi (Pb)2212[12] has been observed in a strong magnetic field. The effect of a strong magnetic field on alignment/growth during solidification presents itself with a large degree of complexity

Results

Discussion

Conclusion