(1. 北京有色金属研究总院 有色金属材料制备加工国家重点实验室,北京100088;
2. 东北轻合金有限责任公司,黑龙江哈尔滨150060)
摘 要: 利用光学显微镜、扫描电子显微镜、能谱分析、差示扫描量热、X射线物相分析研究2D70耐热铝合金半连续铸锭的结晶相及合理的均匀化热处理制度。结果表明:合金半连续铸锭中枝晶偏析严重,存在大量非平衡共晶相,其成分为α(Al)+θ(Al2Cu)+S(Al2CuMg),其初始熔化温度为505.4 ℃;在530 ℃温度以下进行均匀化时,合金中的难溶相Al7Cu2Fe、Al7Cu4Ni、Al9FeNi含量基本没有变化;合金合理的均匀化热处理制度为(490 ℃, 16 h)+(520 ℃, 16 h)。
关键字: 耐热铝合金,均匀化热处理,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