Microstructure and mechanical properties of Mg,Ag and Zn multi-microalloyed Al-(3.2-3.8)Cu-(1.0-1.4)Li alloys

To develop super-high strength Al-Li alloy,the microstructures and mechanical properties of Mg,Ag and Zn microalloyed Al-（3.2-3.8）Cu-（1.0-1.4）Li alloys（mass fraction） with T8 temper were studied.The results showed that 1%of lower Li content restricted the strengthening effect of increasing Cu content,while simultaneous increase in Cu and Li contents contributed effectively to the enhancement of strength.The alloys were mainly strengthened by plenty of fine and well dispersed TI（Al2CuLi）precipitates.There were also some minor precipitates of θ＇（Al2Cu） and δ＇（Al3Li）,which became less in number density,even disappeared during the aging process.Meanwhile,higher Li content favored the formation θ＇ and δ＇ and a small amount of S＂（Al2CuMg） phases.In addition,strengthening effect and microstructure variation were analyzed through total non-solution mole fraction of Cu and Li and their mole ratio.To obtain Al-Li alloy with super-high strength,the total mole fractions of Cu and Li should be increased,and their mole ratios should also be kept at a certain high level.

Cu,Li含量对新型超高强铝锂合金力学性能及微观组织的影响

利用力学性能测试和TEM分析测试手段,计算出铝锂合金Al-(3.6%~4.15%)Cu-(1.1%~1.4%)Li中非固溶Cu,Li原子摩尔分数总和及Cu/Li原子摩尔分数比,分析了强度和微观组织之间的影响机理.结果表明,合金中的主要时效强化相为大量T1相(Al2CuLi)和少量θ′相(Al2Cu),Li含量较高的合金可能析出的极少量δ′相(Al3Li).在上述成分范围内,随Cu含量或Li含量增加,合金强度提高,且Li含量的增加幅度不同,对合金强度的提高幅度存在明显的差异.非固溶Cu,Li原子摩尔分数总和及其比例共同作用,通过影响析出相总量、类型及各析出相分数决定合金强度.要获得铝锂合金的超高强度,在提高Cu,Li原子摩尔分数总和的同时,还要提高其比例.

废旧磷酸铁锂脱锂后的铁磷渣锂吸附性能

以磷酸铁锂正极粉脱锂后的铁磷渣为锂离子筛,高钠锂比的硫酸钠型卤水为原料,系统研究还原剂用量、锂浓度、锂钠比、吸附温度等对铁磷渣锂吸附性能的影响。结果表明,铁磷渣锂吸附性能随着还原剂用量、锂浓度、锂钠比和吸附温度的提高而提升;同时,锂钠选择系数与锂钠比呈正相关性,而与吸附温度呈负相关性。经过5次吸附-解吸附循环后,吸附和解吸附过程的溶损率分别低于0.15%和0.002%;同时,铁磷渣的吸附容量基本稳定在2.7mmol/g,Li/Na选择系数为3.88,表现出较佳的锂吸附性能和循环稳定性能。

碱集料反应预防材料的研究

系统研究了LiOH对两种工程活性集料(北京砾石和沸石化珍珠岩)引起的碱集料反应的影响。研究发现:掺加一定Li/Na摩尔比以上的LiOH能长期有效抑制碱集料反应膨胀。此外,对LiOH抑制碱集料反应的作用机理进行了讨论。