摘要
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 isochronal aging treatment on compressive strength and energy absorption be- havior of the A1-0. 16Sc-0. 08Zr foams with homogeneous pore structure and porosity of 71. 5% 72.5 %, which was fabricated by melt-foam method, were investigated. The results show that the foams exhibit homogeneous spherical pore structure with pore size approximately 0.9 mm. Due to trace Zr con- tent, the absence of primary A1_3 （Zr,Sc） phase in the matrix can be observed. The compressive strength of the alloy foams is increased firstly and then decreased with increasing in temperature during isochronal aging between 200 ℃ and 600 ℃. The sample shows the desirable compressive strength and energy ab- sorption capacity with aged at 400 ℃. The heat treatment can lead to the decrease of the cell-wall plas- ticity, which is beneficial for the energy absorption efficiency and the peak stage prolonging. The micro- structure observation of the cell wall at 400 ℃ shows the precipitation of nano-size A13 （Sc,Zr,Ti） parti- cles existing coherent with A1 matrix with a radius of 2.9-4.8 nm. These AI3 （Sc,Zr,Ti） particles can inhibit the grain boundary sliding and dislocation movement, strengthening the cell walls and improving the compressive strength as well as energy absorption behavior of the foams.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2016年第7期772-776,共5页
Special Casting & Nonferrous Alloys
基金
2015年总装备部预研专项计划资助项目(1501JZJZ0505)
关键词
闭孔泡沫铝合金
压缩性能
能量吸收
纳米析出相
Cellular AI Alloy Foams, Compressive Behavior, Energy Absorption, Nano-Size Precipitates
