Properties of Ceramic Layer Formed by Centrifugal Thermit Reaction with Silicon Sludge Replacement

Abstract

A ceramic-lined steel pipe has been prepared by the thermit reaction of aluminum-ferric oxide under centrifugal force with the partial replacement of aluminum by the silicon sludge obtained from a semiconductor wafer cutting processing. The ceramic layer on the pipe inner surface consists of the crystalline structures of mainly corundum (α-Al₂O₃) and hercynite (FeAl₂O₄). The sludge replacement increases the layer density from 2.9 g/cm³ to 3.5 g/cm³ and the hardness from 1450 Hv to 1780 Hv. The amorphous phases of mullite (Al₆Si₂O₁₃) formed between the crystalline structures are found to be responsible for a significant improvement of the ceramic layer density.