(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 研究了2197鋁鋰合金的高溫拉伸性能以及長時(shí)間熱暴露后的室溫力學(xué)性能，同時(shí)對(duì)合金熱暴露前后的顯微組織進(jìn)行透射電鏡觀察。結(jié)果表明：2197合金的高溫拉伸強(qiáng)度隨拉伸溫度的升高而逐漸降低，在200 ℃下的高溫拉伸性能優(yōu)于傳統(tǒng)高溫用鋁合金；在低于150 ℃的溫度下熱暴露100 h后，2197合金的強(qiáng)度略有上升，這與T1相具有較強(qiáng)的抗粗化能力及θ′相的二次析出有關(guān)；但在200 ℃和250 ℃熱暴露條件下，合金的力學(xué)性能快速下降，這與在此溫度下θ′相的溶解和T1相的快速粗化有關(guān)。
關(guān)鍵字: 2197鋁鋰合金；熱暴露；耐熱性能；T1相
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The tensile properties at elevated temperatures and the room-temperature properties after long time thermal exposure of 2197 alloy were studied. Microstructures of 2197 alloy after long time thermal exposure at different temperatures were observed by TEM. The results show that the tensile strength at elevated temperatures decreases with increasing test temperature, and the tensile properties at 200 ℃ are higher than those of traditional aluminum alloy used at elevated temperature. After exposure at temperatures below 150 ℃ for 100 h, the mechanical properties of 2197 alloy increase slightly. This is related to the high coarsening resistance of T1 phase and secondary precipitation of θ′ phase at these temperatures. However, after exposure at 200 ℃ and 250 ℃ for 100 h, the mechanical properties of 2197 alloy decrease rapidly due to the dissolution of θ′ phase and rapid coarsening of T1 phase at these temperatures.
Key words: 2197 Al-Li alloy; thermal exposure; heat resistant properties; T1 phase
