(1. 湖南科技大學(xué) 高溫耐磨材料及制備技術(shù)湖南省國防技術(shù)重點實驗室，湘潭 411201；
2.湖南科技大學(xué) 難加工材料高效精密加工湖南省重點實驗室，湘潭 411201；
3. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 以第二相變化為基礎(chǔ)，利用掃描電鏡和透射電鏡等組織結(jié)構(gòu)分析手段，結(jié)合云紋干涉法研究Al-Cu-Mg合金在時效過程中的組織結(jié)構(gòu)演變規(guī)律和微尺寸變化規(guī)律。結(jié)果表明：殘余應(yīng)力以及Al2CuMg相的形貌、分布和數(shù)量變化是引起Al-Cu-Mg合金尺寸改變的主要原因。提高Al-Cu-Mg合金中Al2CuMg相的形核率，獲得細(xì)小彌散分布的Al2CuMg相可以極大地降低合金的系統(tǒng)自由能，顯著提高Al-Cu-Mg合金的尺寸穩(wěn)定性。
關(guān)鍵字: Al-Cu-Mg合金；第二相；尺寸穩(wěn)定性；云紋干涉；殘余應(yīng)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
