(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院 有色金屬材料科學(xué)與工程教育部重點(diǎn)實(shí)驗(yàn)室，長沙 410083；2. 長沙大學(xué) 機(jī)電工程系，長沙 410003)
摘 要: 采用光學(xué)顯微鏡、掃描電鏡和透射電鏡等研究7B50高強(qiáng)鋁合金鑄態(tài)和均勻化態(tài)的顯微組織與成分分布，確定了實(shí)驗(yàn)合金一級(jí)均勻化后的過燒溫度及二級(jí)均勻化工藝。結(jié)果表明：實(shí)驗(yàn)合金經(jīng)465 ℃，24 h均勻化后的過燒溫度為480 ℃，其最佳二級(jí)均勻化退火工藝為隨爐升溫到465 ℃保溫24 h，再隨爐升溫到475 ℃保溫4 h；實(shí)驗(yàn)合金經(jīng)二級(jí)均勻化處理后，成分均勻，殘留共晶很少，基體上析出大小適中及分布均勻的Al3Zr質(zhì)點(diǎn)。
關(guān)鍵字: 7B50鋁合金；均勻化；顯微組織
（1. School of Materials Science and Engineering, Key Laboratory of Non-Ferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China;2. Department of Mechanical and Electrical Engineering, Changsha University, Changsha 410003, China）
Abstract:The microstructure and the composition distribution of as-cast and homogenized aluminium alloy 7B50 were studied by means of optical micrography, scanning electron micrography and transmission electron micrography. The overheating temperature of the alloy homogenized at 465 ℃ for 24 h and the two-step homogenization parameters were determined. The results indicate that the overheating temperature of the alloy homogenized at 465 ℃ for 24 h is 480 ℃, and the two-step homogenizing process is optimized. After the studied alloy is treated with the two-step homogenizing process, the alloy elements are uniformly distributed, the pseudoeutectic is little and the Al3Zr particles are uniformly precipitated in the matrix.
Key words: 7B50 aluminum alloy; homogenization; microstructure
