(1. 中南大學(xué) 高性能復(fù)雜制造國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083；
2. 中南大學(xué) 輕合金研究院，長(zhǎng)沙 410083)
摘 要: 通過(guò)掃描電鏡(SEM)、透射電鏡(TEM)和室溫拉伸性能測(cè)試等分析方法，研究再時(shí)效處理對(duì)2219-T6鋁合金叉形環(huán)顯微組織與力學(xué)性能的影響。結(jié)果表明:在170 ℃下再時(shí)效12 h時(shí)，構(gòu)件抗拉強(qiáng)度達(dá)到406 MPa，屈服強(qiáng)度達(dá)到314 MPa，伸長(zhǎng)率為8%，其力學(xué)性能和成形性的綜合效果最佳。延長(zhǎng)時(shí)效時(shí)間，與(170 ℃，12 h)時(shí)效態(tài)相比，第二相粒子出現(xiàn)明顯的團(tuán)聚現(xiàn)象，晶界無(wú)析出帶(PFZ)寬度增加，合金中析出相長(zhǎng)寬比減小，θ″相含量下降，大部分轉(zhuǎn)變成亞穩(wěn)相θ′，部分生成粗大的平衡相θ，其力學(xué)性能明顯下降。
關(guān)鍵字: 2219鋁合金；叉形環(huán)；再時(shí)效；顯微組織；力學(xué)性能
（1.State Key Laboratory of High Performance and Complex Manufacturing,
Central South University, Changsha 410083, China;
2. Light Alloy Research Institute, Central South University, Changsha 410083, China）
Abstract:The effects of reaging on the microstructures and mechanical properties of 2219-T6 alloy fork-like ring were investigated by tensile test, scanning electron microcopy (SEM) and transmission electron microscopy (TEM). The results show that after reaging at 170 ℃ for 12 h, the tensile strength, yield strength and elongation of the fork-like ring are 406 MPa, 314 MPa, 8%, respectively. Increasing the aging time, the mechanical properties of the alloy has fallen greatly because of denser precipitates and wide precipitate free zones (PFZ). Compared to aging treatment (170 ℃, 12 h), the aspect ratio of precipitates decreases and large number of θ″ precipitates transform into θ′ precipitates, some of that become thick θ precipitate.
Key words: 2219 aluminum alloy; fork-like ring; reaging; microstructures; mechanical property
