(1. 東北大學(xué) 材料科學(xué)與工程學(xué)院，沈陽(yáng) 110819；
2. 東北大學(xué) 材料各向異性與織構(gòu)教育部重點(diǎn)實(shí)驗(yàn)室，沈陽(yáng) 110819；
3. 東北大學(xué) 金屬型線材研究中心，沈陽(yáng) 110819)
摘 要: 利用金相顯微鏡(OM)、透射電子顯微鏡(TEM)結(jié)合萬(wàn)能材料試驗(yàn)機(jī)研究Sc含量(質(zhì)量分?jǐn)?shù))從0.034%增大至0.215%時(shí)，Sc含量對(duì)T6態(tài)Al-10Zn-2.5Mg-1.6Cu-0.15Zr鋁合金板材中過(guò)剩結(jié)晶相、彌散相、析出相、晶粒及力學(xué)性能的影響。結(jié)果表明：Sc含量從0.034%增加至0.215%，T相和Al7Cu2Fe相過(guò)剩結(jié)晶相粒子組態(tài)無(wú)明顯變化；納米級(jí)Al3(Sc,Zr)彌散相粒子的尺寸不變但數(shù)量呈現(xiàn)出先增多后減少的趨勢(shì)；析出相粒子尺寸先細(xì)化后粗化，數(shù)量先增多后減少。當(dāng)Sc含量為0.189%時(shí)，合金板材中出現(xiàn)3~5 μm的初生Al3(Sc,Zr)粒子，其數(shù)量隨Sc含量增加而增多。T6態(tài)Al-10Zn-2.5Mg-1.6Cu-0.15Zr-(0.034-0.139)Sc合金板材的晶粒呈纖維狀，且隨Sc含量增加，纖維狀晶粒逐漸細(xì)化、長(zhǎng)度逐漸縮短；當(dāng)Sc含量為0.189%時(shí)，合金板材發(fā)生明顯再結(jié)晶，其晶粒均為細(xì)小類球狀等軸晶；當(dāng)Sc含量從0.034%增加至0.215%，T6態(tài)合金板材的強(qiáng)度和伸長(zhǎng)率均隨Sc含量增加呈現(xiàn)出先升高后降低的趨勢(shì)；當(dāng)Sc含量為0.139%時(shí)，合金板材的性能最佳，其抗拉強(qiáng)度、屈服強(qiáng)度和伸長(zhǎng)率分別為701 MPa、665 MPa和8.0%。
關(guān)鍵字: ScZr復(fù)合合金化；高Zn超高強(qiáng)鋁合金板材；顯微組織；力學(xué)性能
（1. School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China;
2. Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819, China;
3. Research Center for Metallic Wires, Northeastern University, Shenyang 110819, China）
Abstract:The effects of Sc content from 0.034% up to 0.215% on the constituent, dispersoid, precipitate, grain and mechanical properties of Al-10Zn-2.5Mg-1.6Cu-0.15Zr aluminum alloy sheet in T6 temper were investigated by OM, TEM and universal material testing machine. The results show that, with the increase of Sc content from 0.034% to 0.215%, there is no obvious change with the size and quantity of micron T phase and Al7Cu2Fe in Al-10Zn-2.5Mg-1.6Cu-0.15Zr alloy sheet under T6 temper, the size and number of nanoscale precipitate is firstly refined and increase and then coarsened and decrease, whereas the number of the nanoscale Al3(Sc,Zr) dispersoid increases with its size unchanging. When Sc content is 0.189%, there is primary Al3(Sc,Zr) with the size of 3-5 μm in the alloy sheets, and its number increases but the size has no obvious change with the increase of Sc content up to 0.215%. The grains of Al-10Zn-2.5Mg-1.6Cu-0.15Zr-(0.034-0.139)Sc alloy sheets in T6 temper are fibrous, and the fibrous grain gets thinner and shorter with the increase of Sc. When the Sc content is more than 0.189%, the grains of Al-10Zn-2.5Mg-1.6Cu-0.15Zr-(0.189-0.215)Sc alloy sheets in T6 temper are fine equiaxed which means that the recrystallization behavior of alloy sheet is promoted. When Sc content increases from 0.034% to 0.215%, the strength and elongation of alloy sheets in T6 temper firstly increase and then decrease. The alloy sheet in T6 temper with 0.139% Sc has the optimal performance with the tensile strength, yield strength and elongation of 701 MPa, 665 MPa and 8.0%, respectively.
Key words: composite micro-alloying with ScZr; high-Zn ultra high strength aluminum alloy sheet; microstructure; mechanical property
