(中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 采用力學(xué)性能測(cè)試、光學(xué)顯微鏡、掃描電鏡和透射電鏡，研究熱變形溫度和淬火速率對(duì)7085鋁合金組織和力學(xué)性能的影響。結(jié)果表明：隨著熱變形溫度降低，再結(jié)晶體積分?jǐn)?shù)顯著增加，合金的力學(xué)性能先提高后降低；隨著淬火速率的降低，晶界析出相粗化，晶界無沉淀析出帶寬化，合金的力學(xué)性能降低。合金熱變形溫度越低，其淬火敏感性越高，這是由于在緩慢冷卻的過程中，再結(jié)晶引起的大角度晶界和非共格的Al3Zr粒子成為MgZn2 相的有利形核位置，降低合金的時(shí)效強(qiáng)化效應(yīng)。
關(guān)鍵字: 7085鋁合金；熱變形溫度；淬火速率；力學(xué)性能
microstructure and property of 7085 aluminum alloy
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The influences of hot deformation temperature and quench rate on microstructure and property of 7085 aluminum alloy were investigated by tensile testing, optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show decreasing hot deformation temperature can greatly increase the volume fraction of recrystallization, and the mechanical properties firstly increase and then decrease. With the decrease of quenching rate, the size of precipitations coarsens and the width of precipitation free zone widens as well as the mechanical properties decrease. In addition, the lower the deformation temperatures are, the higher the quench sensitivity is, which is attributed to the large volume fraction of recrystallization resulting in a large amount of high angle grain boundaries and incoherent Al3Zr serve as the nucleation sites of η(MgZn2). As a result, the aging-hardening decreases.
Key words: 7085 aluminum alloy; hot deformation temperature; quench rate; mechanical property
