Al-W Alloy Deposition from Lewis Acidic Room-Temperature Chloroaluminate Ionic Liquid

摘要

The electrochemistry of binuclear tungsten salt, K_3[W_2Cl_9], wasexamined in the Lewis acidic 66.7-33.3 mole percent (m/o)aluminum chloride–1-ethyl-3-methylimidazolium chloride (AlCl_3–[EtMeIm]Cl) room-temperature ionic liquid as it pertains to theelectrodeposition of the Al-W alloy. We revealed that Al-W alloywithout chloride contamination can be electrodeposited from the66.7 m/o AlCl_3-[EtMeIm]Cl with the K_3[W_2Cl_9]. Interestingly Al-W alloy having an amorphous phase as well as W-rich Al alloy over96 atomic present (a/o) W were successfully produced. However theAl-W alloy became covered with powdery deposits with increasingthe W content in the alloy. The resulting Al-W alloy showed afavorable chloride-induced pitting potential comparable to thatproduced by a usual sputtering method if the W content was lessthan ca. 3 a/o W.