(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；
3.中南大學(xué)有色金屬先進(jìn)結(jié)構(gòu)材料與制造協(xié)同創(chuàng)新中心，長(zhǎng)沙 410083)
摘 要: 利用金相組織觀察(OM)、掃描電鏡分析(SEM)、透射電鏡觀察(TEM)以及硬度測(cè)試，研究固溶處理對(duì)7B04鋁合金顯微組織及硬度的影響。結(jié)果表明：實(shí)驗(yàn)合金中的η相(MgZn2)為易溶相，S相(Al2CuMg)為難溶相，含F(xiàn)e雜質(zhì)相為不溶相；進(jìn)行單級(jí)固溶處理時(shí)，隨著固溶溫度的升高，實(shí)驗(yàn)合金的固溶程度、再結(jié)晶程度和再結(jié)晶晶粒尺寸增加，當(dāng)溫度超過480℃時(shí)，出現(xiàn)過燒現(xiàn)象，力學(xué)性能惡化，7B04鋁合金淬火敏感性較高；雙級(jí)固溶可有效抑制合金再結(jié)晶、降低合金淬火敏感性，實(shí)驗(yàn)條件下較好的雙級(jí)固溶工藝為(450℃, 0.5h)+(490℃, 0.5h)，抑制合金再結(jié)晶效果最佳，經(jīng)120℃時(shí)效24h后，硬度達(dá)到最大值，為204HV1。
關(guān)鍵字: 7B04鋁合金；雙級(jí)固溶；淬火敏感性；硬度
（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;
3.Nonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Center, Central South University, Changsha 410083, China）
Abstract:The influence of solution treatments on the microstructure and hardness of 7B04 aluminum alloy were investigated by means of optical microscopy(OM), scanning election microscopy(SEM), transmission election microscopy(TEM) and hardness test. The results show that there are the soluble phaseη(Mg(Zn,Al,Cu)2), the poorly soluble phaseS(Al2CuMg) and the insoluble impurity Fe phase (Al7Cu2Fe). The degree of solid solution and recrystallization increases with the solution temperature increasing gradually. When the temperature exceeds 480℃, overburning on 7B04 alloy occurs and the properties was weakened, 7B04 alloy has high quench sensitivity. However, double-stage solution can inhibit recrystallization of the alloy and decrease the quench sensitivity effectively. The excellent strengthening effect can be expected at (450℃, 0.5h)+(490℃, 0.5h) among the experiments, by which the recrystallization of the alloy can be restrained mostly and the hardness can reach to 204HV1 after aging at 120℃ for 24h.
Key words: 7B04 aluminum alloy; double-stage solution; quench sensitivity; hardness
