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以孔隙率为71.5%~72.5%的泡沫Al-0.16Sc-0.08Zr合金为研究对象(熔体发泡法),研究了等时时效对泡沫铝压缩力学性能和能量吸收性能的影响。结果表明,泡沫铝合金孔多呈球形,孔径约为0.9mm;由于Zr添加量较少,基体中并未发现初生Al3(Zr,Sc)相析出;试样经200~600℃等时时效,随时效温度升高,其压缩强度先增加后降低,时效至400℃的试样压缩屈服强度和能量吸收能力最强;时效处理会导致胞壁塑性下降,影响试样屈服平台过程,其能量吸收效率得到显著提高,且高效阶段更持久。TEM结果表明,等时时效至400℃的试样胞壁中弥散分布着大量纳米级共格Al_3(Sc,Zr,Ti)相,粒径为2.9~4.8nm。这些纳米相能钉扎晶界,阻碍位错运动,改善其压缩和吸能性能。
The effects of isochron age on the compressive mechanical properties and energy absorption properties of aluminum foams were investigated with foamed Al-0.16Sc-0.08Zr alloy with porosity of 71.5% -72.5%. The results show that the pores of the foamed aluminum alloy are spherical and the diameter is about 0.9mm. The primary Al3 (Zr, Sc) phase is not precipitated in the matrix due to the small amount of Zr added. When the sample is aged at 200-600 ℃, With the increase of aging temperature, the compressive strength first increases and then decreases, and the compressive yield strength and energy absorption capacity of the specimens aged to 400 ℃ are the strongest. The aging treatment will lead to the decline of cell wall plasticity, which will affect the sample yielding platform process and its energy absorption Efficiency is significantly improved, and the more efficient stage is more durable. TEM results showed that a large number of nano-scale coexistent Al 3 (Sc, Zr, Ti) phases dispersed in the cell wall at the time of isochronous to 400 ℃, the particle size was 2.9-4.8 nm. These nano-phases can pin the grain boundaries, impede dislocation movement and improve their compression and energy absorption properties.