Preparation of Intermetallic Compound Silicide Film by Electrodeposition Using Molten Salt as Medium

点击翻译按钮获取中文摘要

In this work, the preparation of films of molybdenum silicides, which is the most remarkable as a super high-temperature material among silicides, was attempted by the electrodeposition using molten salt as a medium. The original plan to prepare the molybdenum silisides film in this work was as follows ;Si and Mo are deposited by turns, and their alloying can be proceeded in the molten salt at high temperature. As a result, molybdenum silicide film is formed on metal substrate. First the electrodeposition behaviors of Si and Mo were examined to clarify the deposition conditions of them. It was found that Si could be deposited in a film shape to form nickel silicide film by alloying of deposited Si and Ni substrate when the potentiostatic cathodic polarizations were carried out at the potential regions, at which K_2SiF_6 was reduced, using molten NaC1-KC1 containing K_2SiF_6. In order to deposit Mo, the other hand, the potentiostatic cathodic polarization was carried out using molten NaC1-KC1 containing Li_2Mo0_4 and K_2SiF_6. As a result, metallic Mo was deposited by the polarization at lower potential region. In accordance with their deposition conditions of Si and Mo, the electrodepositions of them were carried out by turns. When Mo was deposited after the Si deposition, Mo_3Si film could be formed on nickel siliside. Conversely, when Si was deposited after the Mo deposition, MoSi_2, which has a superior high-temperature properties, was formed in a dendrite shape. Consequently, it was found that molybdenum silicide films were prepared by the electrodeposition using molten salts.