(中南大學 材料科學與工程學院，長沙 411083)
摘 要: 采用光學顯微鏡、差熱分析、掃描電鏡、能譜分析、透射電鏡和X射線衍射研究2124鋁合金鑄態(tài)與均勻化態(tài)的顯微組織演化和成分分布。結果表明：2124鋁合金的鑄態(tài)組織枝晶偏析嚴重，在晶界存在很多低熔點共晶相，合金中元素Cu，Mg和Mn在晶內及晶界分布不均勻；經過均勻化處理后，2124鋁合金組織中的非平衡相逐漸溶解，各組元分布趨于均勻；該合金的過燒溫度為504 ℃，最佳均勻化制度為(490 ℃，24 h)，該制度與均勻化動力學方程得到的結論基本一致。
關鍵字: 2124鋁合金；均勻化處理；顯微組織；動力學
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The evolution of the microstructure and the composition distribution of as-cast and homogenized 2124 aluminum alloy were studied by optical microscopy (OM), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), energy dispersive X-ray diffractometry (EDX), transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The results show that serious dendrite segregation exists in the 2124 alloy ingot, and many eutectic phases with low melting-point exist in the grain boundary. Cu, Mg and Mn elements distribute unevenly from the grain boundary to inside of the alloy. The non-equilibrium eutectic phases dissolve after homogenization, and the grain boundary becomes sparse and all elements become more homogenized. The over-burnt temperature is 504 ℃. And the proper homogenizing process of the 2124 alloy is (490 ℃, 24 h), which is corresponding with the results of homogenizing kinetic equation.
Key words: 2124 aluminum alloy; homogenization treatment; microstructure; kinetics
