(1.中南大學(xué)材料科學(xué)與工程學(xué)院，長(zhǎng)沙410083；
2. 中南大學(xué)有色金屬材料科學(xué)與工程教育部重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙410083)
摘 要: 通過(guò)金相顯微鏡(OM)、掃描電鏡(SEM)、示差掃描量熱法(DSC)和室溫拉伸性能測(cè)試等方法，研究固溶處理對(duì)新型高強(qiáng)耐熱鋁合金Al-5.8Cu-0.6Mg-0.6Ag-0.3Nd合金組織和力學(xué)性能的影響。結(jié)果表明：當(dāng)固溶溫度由510 ℃升高到525 ℃時(shí)，更多的初生相回溶至基體；當(dāng)固溶溫度繼續(xù)升至530 ℃時(shí)，初生相則未進(jìn)一步回溶，而再結(jié)晶晶粒的尺寸持續(xù)加劇，導(dǎo)致合金軟化程度增加；合金的力學(xué)性能由時(shí)效強(qiáng)化和固溶軟化共同影響，該合金優(yōu)化的固溶處理制度為525 ℃、2 h，經(jīng)(525 ℃，2 h)+(185 ℃，7 h)峰時(shí)效處理后，合金抗拉強(qiáng)度、屈服強(qiáng)度和伸長(zhǎng)率分別為608 MPa、587 MPa和10.4%。
關(guān)鍵字: Al-Cu-Mg-Ag-Nd合金；固溶處理；顯微組織；力學(xué)性能
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China）
Abstract:The effects of solution treatment on the microstructures and mechanical properties of new high-strength heat-resistant Al-5.8Cu-0.6Mg-0.6Ag-0.3Nd aluminum alloy were studied by OM, SEM, DSC and room temperature tensile test. The results show that, as the solution temperature increases from 510 ℃ to 525 ℃, the primary phases dissolve in matrix.The amount of primary phase has no change with temperature increasing to530 ℃.But the size increase of the recrystallized particles gradually leads to the increase of alloy softening. The mechanical properties of aged alloy are determined by precipitation strengthening and solution softening, and the suitable solution treatment for Al-5.8Cu-0.6Mg-0.6Ag-0.3Nd alloy is525 ℃ for 2 h. After the solution and peak aging of (525 ℃, 2 h)+(185 ℃, 7 h), the ultimate tensile strength, yield strength and elongation of the aluminum alloyare 608 MPa,587 MPa and 10.4%, respectively.
Key words: Al-Cu-Mg-Ag-Nd alloy; solution treatment; microstructure; mechanical property
