【摘要】 针对单极方波脉冲电流幅值对Al-Cu合金凝固组织的影响进行了试验研究。结果表明,脉冲电流对亚共晶Al-5Cu和过共晶Al-50Cu合金的凝固组织和初生相有明显细化作用,这主要是由于方波脉冲电流频域较宽,高次波的能量衰减较慢,对凝固系统所做的有效功值较高。由于电流及感生磁场的不均匀性而产生的磁场梯度漂移和磁力线曲率漂移,使得过共晶Al-50Cu合金中Al3+及Cu+离子沿磁场方向迁移,在脉冲电场作用下,促使初生相CuAl2沿磁场方向优势生长。更多还原

【Abstract】 The effects of single-polar rectangle wave pulse current on solidification structure of Al-Cu alloy have been observed. It was found that the pulse current can remarkably refine the solidification structure and primary phase in both eutectic Al-5Cu alloy and hypereutectic Al-50Cu alloy, which is attributed to wide frequency scope of the pulse current and low energy fading for high order of harmonic wave improving the useful work for solidification structure. Drift of magnetic field gradient and curvature of magnetic line generated from the heterogeneity of magnetic field resection can result in the migration of Al3+ and Cu+ in the alloy along the magnetic field direction with the pulse current treatment, promoting the oriented growth of primary phase CuAl2 along the magnetic filed direction.更多还原