3003-H16铝合金卷材生产过程中的组织演变

利用热分析仪、光学显微镜、扫描电镜和能谱仪等方法研究了3003-H16铝合金卷材生产过程中的组织演变。结果表明,晶粒尺寸、二次枝晶间距和金属间化合物尺寸从铸锭心部至铸锭表层逐渐减小。当均匀化温度为590 ℃时,α-Al晶体内析出细小颗粒状的Al₆Mn;随均匀化温度的提高,颗粒状析出相不断溶解并促进针棒状析出相长大;当均匀化温度为640 ℃时,针棒状析出相开始溶解,至650 ℃时完全溶解。金属间化合物Al₆(Fe,Mn)和Al₆Mn随均匀化温度的升高而变得圆滑球化,部分Al₆(Fe,Mn)在均匀化过程中转变为Al(Fe,Mn)Si。3003铝合金热轧卷材的晶粒组织在厚度方向上存在不均匀性,冷轧和中间退火后有所改善。3003铝合金卷材中的化合物沿轧制方向成行排列,具有明显的方向性,其中大尺寸化合物的比例随加工率的增大逐渐降低。均匀化可以改善3003铝合金的成分和组织均匀性,改善合金的塑性。变形加工在提高3003铝合金强度的同时降低了合金的塑性。中间退火过程中纤维状的变形组织转变为再结晶组织,消除了硬化现象,合金的塑性得到改善。

Microstructure evolution of 3003-H16 aluminum alloy coil in production process

Microstructure evolution of 3003-H16 aluminum alloy coil in production process was studied by means of thermal analyzer, optical microscope, SEM and EDS. The results show that the grain size, secondary dendrite spacing and the size of grain boundary compounds decrease gradually from center to surface of the ingot. When the homogenization temperature is 590 ℃, fine granular Al₆Mn precipitates in α-Al crystal. With the increase of homogenization temperature, the granular precipitates dissolve continuously and promote the growth of needle-rod precipitates. When the homogenization temperature is 640 ℃, the rod-shaped precipitates begin to dissolve, and completely dissolve at 650 ℃.The intermetallic compounds Al₆(Fe,Mn) and Al₆Mn become smooth and spheroidized with the increase of homogenization temperature, and some Al₆(Fe,Mn) transforms into Al(Fe,Mn)Si during homogenization. The grain structure of the the 3003 aluminum alloy hot rolled coil is non-uniform in thickness direction, which is improved after cold rolling and intermediate annealing. The compounds in the 3003 aluminum alloy coil are arranged in rows along the rolling direction, with obvious directionality. The proportion of large-sized compounds decreases with the increase of reduction ratio. Homogenization can improve the composition and microstructure uniformity of the 3003 aluminum alloy and improve the plasticity of the alloy. Deformation processing can improve the strength of the 3003 aluminum alloy and reduce the plasticity of the alloy. The fibrous deformed structure is transformed intorecrystallized structure during the intermediate annealing, which eliminates the hardening phenomenon and improves the plasticity of the alloy.