(1. 中南大學(xué) 輕合金研究院，長沙 410083；
2. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083；
3. 中車長春軌道客車股份有限公司，長春 130062)
摘 要: 采用鑄錠冶金法制備出不同Sc含量的6005A合金鑄錠，合金鑄錠經(jīng)均勻化、熱軋、中間退火、冷軋成2.5 mm厚的薄板，研究Sc含量對6005A合金拉伸性能、晶粒大小、金相組織及其相組成的影響。結(jié)果表明：微量Sc可提高6005A合金的強(qiáng)度，其中含0.07%Sc的合金具有最佳的拉伸性能，其抗拉強(qiáng)度、屈服強(qiáng)度分別提高19 MPa、47 MPa，伸長率也提高1.2%；添加微量Sc的合金晶粒得到細(xì)化，且隨著Sc含量的增加，細(xì)化效果越明顯；添加微量Sc減合金中枝晶的偏析，形成彌散的Al3Sc相，抑制合金的再結(jié)晶；隨著Sc含量的增加，晶內(nèi)彌散的Mg2Si相得到細(xì)化。
關(guān)鍵字: 6005A合金；Sc；微合金化；Al3Sc相
（1. Research Institute of Light Alloy, Central South University, Changsha 410083, China;
2. College of Materials Science and Engineering, Central South University, Changsha 410083, China;
3. CRRC Changchun Railway Vehicles Co., Ltd., Changchun 130062, China）
Abstract:The 6005A alloy ingots with different Sc contents were prepared by ingot metallurgy (IM). And the alloy ingots were homogenized, hot rolled, intermediate annealed and cold rolled into 2.5 mm thick sheets. The effects of Sc content on the tensile properties, grain size, metallographic structure and phase composition of 6005A alloy were studied. The results show that the strength of 6005A alloy can be improved by trace Sc, and the alloy containing 0.07% Sc has the best tensile properties. The tensile strength and yield strength are increased by 19 MPa and 47 MPa, respectively, and the elongation is also increased by 1.2%. The grain of the alloy with trace Sc is refined, and the refining effect is better with the increase of Sc content. The addition of trace Sc reduces the segregation of dendrite in the alloy, forms dispersed Al3Sc phase, and inhibits the recrystallization of the alloy. With the increase of Sc content, the dispersed Mg2Si phase is refined.
Key words: 6005A alloy; Sc; microalloying; Al3Sc phase
