CONTROL OF SOLIDIFIED STRUCTURES AND INTERGRANULAR PRECIPITATIONS IN Al-Li BINARY ALLOYS BY HIGH MAGNETIC FIELDS
The present study is undertaken to investigate the effects of high magnetic fields on the solidified structure and grain boundary of binary Al-Li alloy. Al-3wt.％Li alloys were solidified under both uniform and gradient magnetic field conditions. The secondary dendrite arm spacing (SDAS) and area fraction of grain boundary (AFGB) on the longitudinal section of the alloys were measured using metallographic analysis. Morphology and patterns of the precipitates were also analyzed using optical microscopy, scanning electron microscope (SEM), transmission electron microscopy (TEM) and auger electron spectroscopy (AES). It was found that, when imposing a high uniform magnetic field, the SDAS decreased, while the high gradient magnetic fields were observed to have no more obvious effect than the uniform ones on the SDAS. AES and TEM analysis showed that in all cases, the precipitated phases at grain boundary and in a matrix were δ (AlLi) and δ (Al<3>Li) phases, respectively. Furthermore, the AFGB decreased at first and then increased with increase of the magnetic flux density under uniform magnetic field, while it decreased in the case of high gradient magnetic field.
High magnetic field Al-Li alloy Solidified structure Precipitation Secondary dendrite arm spacing Grain boundary
Tie LIU Qiang WANG Ke WANG Yi YUAN Hongwei ZHANG Keiji Nakajima -Jicheng He
Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern Univ Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern Univ
国际会议
大连
英文
607-612
2007-08-19（万方平台首次上网日期，不代表论文的发表时间）