(1. 北京科技大学 新金属材料国家重点实验室，北京 100083；
2. 河海大学 力学与材料学院，南京 210098；
3. 常州市河海科技研究院有限公司，常州 213164)
摘 要: 采用熔体发泡法制备孔隙率为71.5%~72.5%、孔结构均匀的泡沫Al-0.2Sc-0.17Zr合金。研究孔结构、胞壁显微组织以及等时时效对其压缩和能量吸收性能的影响。结果表明：泡沫铝合金的孔径约为1 mm，且多呈球形；初生Al3(Zr，Sc，Ti)相具有层状结构，并能有效细化铸态晶粒(尺寸约为50 μm)；在200~600 ℃等时时效过程中，泡沫试样的压缩性能随温度升高呈现先升高后下降的趋势，325和425 ℃分别表现出由Sc和Zr大量析出引起的两个明显的强度峰；时效至425 ℃时试样的能量吸收能力最强，且峰值时效附近的试样能量吸收效率均得到提高，高效阶段更持久；TEM实验结果表明，时效至425 ℃的泡沫铝试样胞壁中弥散分布着大量细小、共格的二次Al3(Sc，Zr，Ti)相，其粒径为2.1~4.1 nm，这些相能钉扎晶界，阻碍位错运动，因而能显著提高泡沫铝合金的压缩和吸能性能。
关键字: 闭孔泡沫铝钪锆合金；压缩性能；能量吸收；纳米析出相
（1. State Key Laboratory for Advanced Metals and Materials,
University of Science and Technology Beijing, Beijing 100083, China;
2. School of Mechanics and Materials, Hohai University, Nanjing 210098, China;
3. Hohai Science & Technology Research Institute Co., Ltd., Changzhou 213164, China）
Abstract:Cellular Al-0.2Sc-0.17Zr foams with homogeneous pore structure and porosity of 71.5%-72.5% were fabricated by melt-foaming method. The effects of the pore structure, microstructure and isochronal aging on the compressive strength and energy absorption properties of the foams were investigated. The results show that the foams have homogeneous pore structure with pore size of about 1 mm. The primary Al3(Zr,Sc,Ti) phase with core/shell structure can refine the grain size to about 50 μm. The compressive strength first increases and then decreases during isochronal aging between 200 and 600 ℃. Two strength-peaks appear in the aging process at 325 and 425 ℃ due to the precipitation of Sc and Zr from the matrix, respectively. The isochronal aging is also beneficial to the improvement of energy absorption capacity and efficiency. The sample heat-treated at 425 ℃ shows the best energy absorption capacity, and the high energy absorption efficiency stages for all the samples around the peak aging are prolonged. The TEM observation of the cell wall at 425 ℃ confirms the precipitation of nano-size Al3(Sc,Zr,Ti) particles that are coherent with Al matrix with a radius of 2.1-4.1 nm. This suggests that these Al3(Sc,Zr,Ti) particles can inhibit the grain boundary sliding and dislocation movement, thus, strengthening the cell walls and increasing the compressive strength and energy absorption properties of the foams.
Key words: cellular Al-Sc-Zr alloy; compressive property; energy absorption; nano-size precipitate
