LAUSR

Fe-W-mullite-based composite coatings were prepared on the inner-surface steel pipe from two reactions of Fe(Mn)WO4-Fe2O3-Al-Si and Fe(Mn)WO4-Fe2O3-B2O3-Al-Si mixture powder by centrifugal-SHS process. Standard Gibbs energy minimization method was used to compute the adiabatic temperature (Tad) and predict equilibrium composition of the products. The composite coatings consisted of two layers of alloy (α) and ceramic (β) which were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX). Surface roughness, hardness, and adhesive strength properties of the coating layer were investigated by profilometer, Vickers microhardness, and compression-shear test, respectively. In addition, the effects of adding Fe to the system was studied. It was found that the composite coating from the reaction of Fe(Mn)WO4-Fe2O3-Al-Si with 1.4 wt% Fe provided the smoothest surface, highest hardness, and adequate adhesive strength.