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

A ceramic-lined steel pipe has been prepared by the thermit reaction of aluminium-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 (alpha-Al2O3) and hercynite (FeAl2O4). The sludge replacement increase the layer density from 2.9 g/cm(3) to 3.5 g/cm(3) and the hardness front 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.