Mn、Fe质量比对挤压铸造Al-Cu合金组织与性能的影响

Effects of Mn、Fe Mass Ratio on Microstructure and Mechanical Properties of Squeeze Casting Al-Cu Alloy

研究了不同Mn、Fe质量比和挤压压力对Al-Cu合金显微组织与力学性能的影响,并分析了其作用机理。结果表明,不同w（Mn）/w（Fe）的Al-Cu合金中主要存在4种富Fe第二相,即鱼骨状AlmFe、块状ɑ-Fe和Alm（FeMn）相以及针状β-Fe相;挤压压力为70 MPa时,合金中富Fe相相较于压力为0时更加细小和分散,且合金中针状β-Fe相在w（Mn）/w（Fe）为0.8时基本消失;而挤压压力为0,w（Mn）/w（Fe）为1.6时才基本消失;随着合金中w（Mn）/w（Fe）和挤压压力的增加,富Fe相圆整度提高,但是并不能显著改变合金中鱼骨状富Fe相的尺寸;挤压压力为0,Al-Cu合金在w（Mn）/w（Fe）为1.6时取得力学性能最佳值,而挤压压力为70 MPa时合金的最佳力学性能出现在w（Mn）/w（Fe）为1.2时。

The effects of varied Mn、Fe mass ratio and extrusion pressure on the microstructure and mechanical properties of Al-Cu alloy were investigated,and the mechanism was described.The results show that there exist mainly four kinds of Fe-enrichment phase in Al-Cu alloy with different Mn、Fe mass ratio,such as the fishbone AlmFe,massiveɑ-Fe,blocky Alm（FeMn）and acicularβ-Fe phase.The Fe-enrichment phase is finer and more dispersed under the extrusion pressure of 70 MPa compared to that in the pressure of 0,and the acicularβ-Fe phase in the alloy almost disappears when the Mn、Fe mass ratio is 0.8,while with extruding pressure of 0,acicularβ-Fe phase almost disappears with Mn、Fe mass ratio of 1.6.With the increase of Mn、Fe mass ratio and extrusion pressure of Al-Cu alloy,the roundness of Fe-enrichment phase is improved,however,the change of size of fishbone like Fe-enrichment phase in the alloy is absent.When the extrusion pressure is 0,the optimum mechanical properties of Al-Cu alloy are obtained when the Mn、Fe mass ratio is 1.6,while the extrusion pressure is 70 MPa,the optimum mechanical properties of the alloy appear when the Mn、Fe mass ratio is 1.2.