Study of formulations and the manufacturing variables of a ceramic weld backing

Abstract

This paper presents a methodology for the in-lab manufacturing of a ceramic backing for the one-sided steel welds. Formulations were prepared using cordierite, bauxite, and magnesite as refractory minerals. Bentonite and sodium silicate were used as additives for the ceramic blend. The manufacturing process included dry mixture, compressing, drying, and sintering of the specimens. The weld backings were characterized by X-ray diffraction, optical microscopy of the surface, water absorption, and flexible voltage. They were also submitted to the welding of the root pass with the MIG–MAG process. The results show that the conventional ceramic manufacturing process is adequate for the production of the ceramic weld backing. Among the tested formulations, cordierite showed better integrity both during its manufacturing and during the welding operation, producing well-shaped weld beads, free from discontinuities. Manufacturing variables were evaluated such as compacting pressure, sintering temperature, and the amount of water added to the ceramic mass.