Electrodeposition of supersaturated aluminum-based solid solutions for maximizing strength and corrosion resistance

合金化强化后的铝（Al）在变形和/或时效过程中，由于α-Al基体中存在粗大的金属间化合物（IMPs），其强度和耐蚀性之间存在矛盾。在本研究的第一阶段，采用典型的1-乙基-3-甲基咪唑氯盐（[EMIm]Cl）-氯化铝（AlCl 3）离子液体（ILs）制备了Al（Fe）过饱和固溶体，并通过光谱和从头算研究了Fe 2+的配位。TEM和XRD表明，Fe（1.5- 14.1at.%）能完全溶解在α-Al基体中，其含量由镀液中FeCl 2浓度控制。纳米压痕和循环极化曲线表明，Fe固溶度较高的Al（Fe）合金具有良好的硬度和耐点蚀性能，而新型四元磷基离子液体（[P14，6，6，6] Cl-AlCl 3）可使Al（Si，3-6 at.%）在室温下，过饱和固溶体，而其性能，包括硬度和耐腐蚀性需要进一步的研究。

Aluminum (Al) strengthened through alloying followed by the deformation and/or aging is inherently subject to the conflict between strength and corrosion resistance due to coarse intermetallic particles (IMPs) in α-Al matrix. Accordingly, supersaturated solid solutions with a homogenous microstructure are proposed to defeat that conflict.In the first stage of this research, the Al(Fe) supersaturated solid solutions have been obtained using typical 1-ethyl-3-methylimidazolium chloride ([EMIm]Cl)－aluminum chloride (AlCl3) ionic liquids (ILs), where the coordination of dissolving Fe2+ have been clarified by spectroscopies together with ab initio calculation. The TEM and XRD demonstrated that Fe (1.5－14.1 at.%) could completely dissolve into α-Al matrix, and its contents were controlled via iron(II) chloride (FeCl2) concentrations in baths. Especially, these Al(Fe) alloys with higher Fe solid solubility prove to attain a simultaneous improvement in hardness and pitting corrosion resistance based on nanoindentation and cyclic polarization curves respectively.In addition, our newly developed quaternary phosphonium-based ILs ([P14,6,6,6]Cl－AlCl3) could give Al(Si, 3－6 at.%) supersaturated solid solutions at room temperature, while their properties including hardness and corrosion resistance require further studies.