Characterization and Optimization of Ni-WC Composite Weld Matrix Deposited by Plasma-Transferred Arc Process

• DOI: 10.1007/s11661-016-3917-5
• Publication Date: 2017-01-05T18:46:02Z
• Authors: Ali Tahaei; Paul Horley; Mattia Merlin; David Torres-Torres; Gian Luca Garagnani; Rolando Praga; Felipe J. García ...; Ana Arizmendi-Mor...
• Keywords: 0203 mechanical engineering; Materials Science (all); Condensed Matter Physics; Mechanics of Materials; 2506; 02 engineering and technology

This work is dedicated to optimization of carbide particle system in a weld bead deposited by PTAW technique over D2 tool steel with high chromium content. The paper reports partial melting of the original carbide grains of the Ni-based filling powder, and growing of the secondary carbide phase (Cr, Ni) $$_3$$ W $$_3$$ C in the form of dendrites with wide branches that enhanced mechanical properties of the weld. The optimization of bead parameters was made with design of experiment methodology complemented by a complex sample characterization including SEM, EDXS, XRD, and nanoindentation measurements. It was shown that the preheat of the substrate to a moderate temperature 523 K (250 $$^\circ $$ C) establishes linear pattern of metal flow in the weld pool, resulting in the most homogeneous distribution of the primary carbides in the microstructure of weld bead.