微量Cu和形变热处理对Al-Fe合金性能的影响

观察Al-Fe合金的显微组织并测量其力学性能和导电性能，研究了Cu元素和形变热处理对其性能的影响。结果表明：在铸态Al-Fe-Cu合金组织中，Cu元素在基体内均匀分布，而Fe元素在晶界处偏析；挤压态的Al-0.7Fe-0.2Cu合金其性能最优：导电率为59.90%IACS，抗拉强度为108 MPa，硬度为31.2HV；随着退火温度的提高Al-0.7Fe-0.2Cu合金的抗拉强度急剧降低，在400℃退火时其抗拉强度最低(100 MPa)，伸长率最高(31.3%)；在250℃退火时导电率出现峰值(62.61%IACS)。在退火Al-0.7Cu-0.2Cu合金中有许多细小针状的θ(Al₂Cu)相析出，并与位错交互缠结。随着退火温度的提高合金中的位错密度降低，晶粒细化。

Effect of Minor-Cu Addition and Thermomechanical Treatment on Properties of Al-Fe Alloy

The effect of minor-Cu addition and thermomechanical treatment on the microstructure and properties of Al-Fe alloy was investigated by means of optical microscopy, SEM, tensile test, and conductivity measurement. The results show that Cu was evenly distributed in the matrix of as-cast Al-Fe-Cu alloy, while the Fe segregated at grain boundary. After extrusion the properties of Al-0.7Fe-0.2Cu alloy reached the optimum, the conductivity was 59.90% IACS, the tensile strength was 108 MPa, and the hardness was 31.2HV. The tensile strength of Al-0.7Fe-0.2Cu alloy decreased sharply with the increase of annealing temperature. The tensile strength was the lowest (100 MPa) after annealing at 400℃, while the elongation was the highest (31.3%). The peak electrical conductivity of Al-0.7Fe-0.2Cu alloy was 62.61% IACS after annealing at 250℃. In addition, many fine needle-like θ(Al₂Cu) phase precipitated during annealing in Al-0.7Cu-0.2Cu alloy, which interacted with dislocations. With the increase of annealing temperature, dislocation density decreased and grain refinement occurred.