2011 Volume 16 Pages 27-32
Electrical discharge machined surface using the silicon (Si) electrode has excellent corrosion resistance because of the formation of an amorphous layer. In this study, Si-containing amorphous layer which was comparatively thick (about 10 μ m) was formed by electrical discharge coating, and the characteristics of this layer were investigated. Detailed metallographic analyses showed that the Si-containing amorphous layer had 7wt% of Si and the fine structures with crystalline existed in this layer. From the water jet test, it became clear that the Si-containing amorphous layer had excellent erosion resistance in addition to excellent corrosion resistance. Furthermore, the Si-containing amorphous layer had comparatively low friction coefficient and high wear resistance. The heating test showed that the Si-containing amorphous layer was kept amorphous in 500 degrees or less and that when the heating temperature exceeded 600 degrees, the layer crystallized so that the microcrystals of Fe3C and α-Fe were deposited.
