(1. 湖南科技大學(xué) 高溫耐磨材料及制備技術(shù)湖南省國(guó)防技術(shù)重點(diǎn)實(shí)驗(yàn)室，湘潭 411201；
2. 南昌航空大學(xué) 航空制造工程學(xué)院，南昌 330063；
3. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: Al-Cu-Mg合金廣泛應(yīng)用于陀螺儀導(dǎo)航系統(tǒng)，其在長(zhǎng)期熱暴露環(huán)境下的尺寸穩(wěn)定性是影響導(dǎo)航精度的關(guān)鍵。本文以第二相和殘余應(yīng)力演變?yōu)榛A(chǔ)，利用X射線和球差透射電鏡等微觀結(jié)構(gòu)分析手段，研究了長(zhǎng)期熱暴露作用對(duì)Al-Cu-Mg合金微尺寸變化的影響。結(jié)果表明：隨著熱暴露時(shí)間的增加，殘余應(yīng)力逐漸降低，Al2CuMg相則逐漸析出并長(zhǎng)大，這使得合金的相對(duì)尺寸變化首先顯著降低，之后輕微增加。合金的相對(duì)尺寸首先下降主要與殘余應(yīng)力釋放有關(guān)，而之后上升則源于Al2CuMg相形貌的改變。與鋁合金基體相比，Al2CuMg相會(huì)導(dǎo)致約5%的橫向體積膨脹。
關(guān)鍵字: Al-Cu-Mg合金；第二相；微尺寸變化；殘余應(yīng)力
（1. Key Lab of High Temperature Wear Resistant Materials Preparation Technology of Hunan Province, Hunan University of Science and Technology, Xiangtan 411201, China;
2. School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University, Nanchang 330063, China;
3. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Al-Cu-Mg alloy is widely utilized as the key component of gyroscope navigation system, and its dimensional stability under the service environment is the determinant for navigation reliability. Based on the evolution of the second phases and residual stress, the corresponding mechanisms of long-time thermal exposure on the dimensional change of Al-Cu-Mg alloy were identified by XRD and HRTEM. The results show that with the increase of exposure time, the residual stress is released and Al2CuMg phases are gradually precipitated and coarsened. Meanwhile, the relative dimensional change firstly shows significant decrease and then slight increase. The dimensional change of this alloy is mainly associated with the release of residual stress at first and then related to the shape variation of Al2CuMg phase, which leads to about 5% transverse expansion in comparison with the Al matrix.
Key words: Al-Cu-Mg alloy; second phase; dimensional change; residual stress
