(1. 北京有色金屬研究總院 有色金屬材料制備加工國(guó)家重點(diǎn)實(shí)驗(yàn)室，北京100088；
2. 東北輕合金有限責(zé)任公司，黑龍江哈爾濱150060)
摘 要: 利用光學(xué)顯微鏡、掃描電子顯微鏡、能譜分析、差示掃描量熱、X射線物相分析研究2D70耐熱鋁合金半連續(xù)鑄錠的結(jié)晶相及合理的均勻化熱處理制度。結(jié)果表明：合金半連續(xù)鑄錠中枝晶偏析嚴(yán)重，存在大量非平衡共晶相，其成分為α(Al)+θ(Al2Cu)+S(Al2CuMg)，其初始熔化溫度為505.4 ℃；在530 ℃溫度以下進(jìn)行均勻化時(shí)，合金中的難溶相Al7Cu2Fe、Al7Cu4Ni、Al9FeNi含量基本沒(méi)有變化；合金合理的均勻化熱處理制度為(490 ℃, 16 h)+(520 ℃, 16 h)。
關(guān)鍵字: 耐熱鋁合金，均勻化熱處理，共晶相
semicontinous casting ingot of 2D70 heat-resistance aluminum alloy
（1. State Key Laboratory of Nonferrous Metals and Processes,
General Research Institute for Nonferrous Metals，Beijing 100088, China;
2. Northeast Light Alloy Co., Ltd., Harbin 150060, China）
Abstract:The constituents of the semicontinuous casting ingot of 2D70 heat-resistance aluminum alloy and homogenization treatment were studied by optical microscopy (OM), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX),differential scanning calorimetry(DSC) and X-ray diffraction analysis (XRD). The results indicate that the semicontinuous casting ingot of 2D70 aluminum alloy presents a dendritic microstructure with severe segregation. The phases of the nonequilibrium eutectic are α(Al)+ θ(Al2Cu) +S(Al2CuMg) whose overheating temperature is 505.4 ℃. The volume fraction of hard dissolve phases such as Al7Cu2Fe, Al7Cu4Ni and Al9FeNi changes a little below 530 ℃. The reasonable homogenization treatment process of the alloy is (490 ℃, 16 h) +(520 ℃, 16 h).
Key words: heat-resistance aluminum alloy; homogenization treatment; eutectic
