微量钪对经不同工艺时效处理的7075铝合金组织和性能的影响

Effect of a Trace of Sc on Microstructure and Property of 7075 Aluminum Alloy Aged by Different Processes

对7075铝合金添加微量的钪。研究了含钪7075铝合金板材经不同工艺时效处理后的组织和性能。结果表明,钪的添加提高了7075铝合金的抗拉强度和电导率。在钪添加量为0.20%时,轧制态7075铝合金的抗拉强度为278.05 MPa,比未添加钪的合金提高了约30.52%。T6处理后7075合金的抗拉强度最高为541.10 MPa,硬度为172.50 HV,电导率为24.95%IACS,电导率提高了约22.40%。此外,含0.20%钪的7075铝合金经120℃×8 h+180℃×18 h双级时效处理后抗拉强度为479.60 MPa,电导率为28.17%IACS,与T6处理相比,抗拉强度降低了11.40%,电导率提高了12.90%。

A trace of scandium was added to 7075 aluminum alloy. Mierostructures and properties of the 7075 alloy plate with scandium aged by different processes was investigated. The results show that the addition of scandium rendered both tensile strength and conductivity of the 7075 aluminum alloy higher. The tensile strength of as-rolled 7075 alloy with 0.20% Sc is 278.05 MPa, and 30.52% higher than that of the one without Sc. The maximum tensile strength of the 7075 alloy subjected to T6 treatment is as high as 541.10 MPa, hardness being 172.50 HV, conductivity being 24.95% IACS and increasing by about 22.40%. Moreover, the tensile strength is 479.60 MPa, and the conductivity is 28.17% IACS for the 7075 alloy with 0.20% Sc subjected to two-stage aging at 120 ℃ for 8 h and then at 180 ℃ for 18 h, being a 11.40% increase and a 12.90% decrease respectively as compared with those of the 7075 alloy with 0.20% Sc subjected to T6 treatment.