(1. 湖南科技大学 高温耐磨材料及制备技术湖南省国防技术重点实验室，湘潭 411201；
2.湖南科技大学 难加工材料高效精密加工湖南省重点实验室，湘潭 411201；
3. 中南大学 材料科学与工程学院，长沙 410083)
摘 要: 以第二相变化为基础，利用扫描电镜和透射电镜等组织结构分析手段，结合云纹干涉法研究Al-Cu-Mg合金在时效过程中的组织结构演变规律和微尺寸变化规律。结果表明：残余应力以及Al2CuMg相的形貌、分布和数量变化是引起Al-Cu-Mg合金尺寸改变的主要原因。提高Al-Cu-Mg合金中Al2CuMg相的形核率，获得细小弥散分布的Al2CuMg相可以极大地降低合金的系统自由能，显著提高Al-Cu-Mg合金的尺寸稳定性。
关键字: Al-Cu-Mg合金；第二相；尺寸稳定性；云纹干涉；残余应力
（1. Hunan Provincial Key Defense Laboratory of High Temperature Wear-resisting Materials and Preparation Technology, Hunan University of Science and Technology, Xiangtan 411201, China;
2. Hunan Provincial Key Laboratory of High Efficiency and Precision Machining of Difficult-to-cut Material, Hunan University of Science and Technology, Xiangtan 411201, China;
3. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Based on the evolution of the second phases, the microstructure was identified by SEM and TEM, while the micro-dimensional change could be measured by Moire interference method. The results show that the main reasons affecting the dimensional change of Al-Cu-Mg are the residual stress, morphology, distribution and quantity of Al2CuMg. Increasing the nucleation rate and obtaining fine distributed Al2CuMg phases can sharply decrease the alloy free energy, and thus enhancing the dimensional stability of the Al-Cu-Mg alloy.
Key words: Al-Cu-Mg alloy; second phase; dimensional stability; Moire interference; residual stress
