电磁搅拌对Al-14Ce合金初生/共晶相与力学性能的影响

Effects of electromagnetic stirring on the primary/eutectic phase and mechanical properties of Al-14Ce alloy

  • 摘要: 针对Al-14Ce合金中富Ce相粗大引起强化效果不佳的问题,通过正交分析法和单一变量法研究电磁搅拌对合金富Ce相及力学性能的影响。结果表明,搅拌频率21 Hz,搅拌电流50 A,搅拌方向为连续正转下,合金获得较优力学性能。抗拉强度达184.6 MPa,屈服强度达107.6 MPa,伸长率达7.06%。在10~50 A范围内,随着搅拌电流的增加,Al11Ce3相平均尺寸先减小后增加,力学性能随之先降低后提升。电流过大达70 A易导致粗大初生相与孔洞缺陷的产生而恶化性能;在7~21 Hz范围内,随着搅拌频率的提升,Al11Ce3相逐渐细化使得力学性能逐步提升。频率过大达28 Hz时则会导致初生相聚集粗化降低力学性能;连续正转利于合金组织与性能改善,交替搅拌会导致局部区域Al11Ce3相聚集生长而恶化性能。

     

    Abstract: Aiming at the poor reinforcement caused by coarse Ce-rich phase in Al-14Ce alloys, the effects of electromagnetic stirring on the Ce-rich phase and mechanical properties during alloy solidification were studied by orthogonal analysis and single variable method. The results show that when the stirring frequency is 21 Hz, the stirring current 50 A and the stirring direction a continuous positive turn, the optimal mechanical properties of the alloy are obtained. The tensile strength reaches 184.6 MPa, the yield strength 107.6 MPa and the elongation rate 7.06%. In the range of 10 to 50 A, with the increase of stirring current, the average size of Al11Ce3 phase decreases first and then increases, and the mechanical properties decreases first and then increases accordingly. Excessive current up to 70 A is easy to cause coarse primary phase and hole defects, thereby deteriorating the performance. In the range of 7 to 21 Hz, with the increase of stirring frequency, the gradual refinement of Al11Ce3 phase gradually improves the mechanical properties. However, excessive frequency up to 28 Hz will lead to the aggregation and coarsening of the primary phase, thereby reducing the mechanical properties. Continuous positive rotation is conducive to the alloy organization and performance improvement, while alternating stirring will lead to the aggregation and growth of Al11Ce3 phase in the local area and thus deteriorates the properties.

     

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