(南昌航空大学 轻合金加工科学与技术国防重点学科实验室,南昌 330063)
摘 要: 采用SEM和XRD等手段,分析励磁电流和凝固压力对ZL205A合金中θ(Al2Cu)相的生长取向及形貌的影响,探讨交变磁场-真空差压协同场下ZL205A合金中θ(Al2Cu)相的生长特性。结果表明,交变磁场-真空差压协同作用对ZL205A合金中θ(Al2Cu)相的生长取向以及形貌的影响显著。随着励磁电流的增大,ZL205A合金的择优生长取向面(110)、(211)、(112)、(310)和(202)逐渐被抑制,当励磁电流增加至10 A时,(112)晶面已经完全被抑制,同时ZL205A合金中θ(Al2Cu)相形貌出现了粗化现象;当励磁电流超过10 A增加至15 A时,θ(Al2Cu)相的择优生长取向只剩(110)和(211)两个晶面,其他生长取向被完全抑制,而大部分θ(Al2Cu)相组织由连续的树枝网络状转变为细小的碎片状;随着凝固压力的增加,ZL205A合金中θ(Al2Cu)相的主要择优生长取向面(110)、(211)、(112)和(202)被逐渐抑制,θ(Al2Cu)相的细化效果越来越显著;励磁电流为15 A、凝固压力为350 kPa时,交变磁场与凝固压力协同作用效果最佳。
关键字: 交变磁场;凝固压力;θ(Al2Cu)相;生长取向;形貌
(National Defence Key Discipline Laboratory of Light Alloy Processing Science and Technology Institute, Nanchang Aeronautical University, Nanchang 330063, China)
Abstract:The effects of excitation current and solidification pressure on the growth orientation and morphology of θ(Al2Cu) phase in ZL205A alloy were analyzed by means of SEM and XRD. The growth characteristics of θ(Al2Cu) phase in ZL205A alloy under alternating magnetic field-vacuum counter-pressure were investigated. The results show that the synergistic effect of alternating magnetic field-vacuum counter-pressure on the growth orientation and morphology of θ(Al2Cu) phase in ZL205A alloy is significant. With the increase of excitation current, the preferred growth orientation planes (110), (211), (112), (310) and (202) of ZL205A alloy are gradually suppressed. When the excitation current is increased to 10A, the (112) crystal plane is completely suppressed, and the θ(Al2Cu) phase morphology in ZL205A alloy is coarsened. When the excitation current exceeds 10 A and increases to 15 A, the preferred growth orientations of θ(Al2Cu) phase are only (110) and (211), and the other growth orientations are completely suppressed. And most of the θ(Al2Cu) phase structure changes from a continuous branch network to a fine fragment. With the increase of solidification pressure, the main growth preferred orientation planes (110), (211), (112) and (202) of θ(Al2Cu) phase in ZL205A alloy are gradually suppressed, and the refinement effect of θ(Al2Cu) phase is more remarkable. Meanwhile, the optimal synergistic effect is obtained when the excitation current is 15 A and solidification pressure is 350 kPa.
Key words: alternating magnetic field; solidification pressure; θ(Al2Cu) phase; growth orientation; morphology