【摘要】 研究了在直流磁场下凝固的7075铝合金晶内溶质含量及凝固组织的变化。试验结果表明与未施加磁场的试样相比,经过直流磁场处理后,7075铝合金中Zn、Mg、Cu3种溶质元素在晶粒内部的含量均增加。此外,直流磁场作用下,试样宏观组织的变化不明显,而晶内析出相的形貌和尺寸发生了显著变化,由无磁场时的粗大针状组织变为细小均匀的结构。探讨了磁场的作用机制。认为电磁场作用使得各溶质粒子对基体铝产生了相对运动,这种运动增强了溶质粒子在铝中的扩散,从而导致了晶内溶质含量的增加。更多还原

【Abstract】 Changes of solute content in grain and solidification structure of 7075 aluminum alloys under a stationary magnetic field were investigated. The experimental results show that Zn, Mg, Cu contents in grain of stationary magnetic field treated 7075 aluminum alloy can be increased compared with those of samples without magnetic field treatment. In addition, the macro-structure of the treated alloy samples can hardly change while the precipitated phase in grain transform from coarse needle-like structure without magnetic field treatment to fine and even structure. The operation mechanism of magnetic field is approached. It is concluded that electromagnetic field can make the relative motion between solute element and aluminum matrix, which increases the diffusion of solute elements in liquid Al, resulting in the increase of the solute content in grain.更多还原