Influence of process parameters on the particle–matrix interaction of WC-Co metal matrix composites produced by laser-directed energy deposition

• Published in: Materials & design 2022-11, Vol.223, p.111172, Article 111172
• Main Authors: Ostolaza, Marta, Arrizubieta, Jon Iñaki, Queguineur, Antoine, Valtonen, Kati, Lamikiz, Aitzol, Flores Ituarte, Iñigo
• Format: Article
• Language: English
• Subjects: Cobalt-base alloy; Diffusion; Metal Matrix Composites; Multi-material l-DED; Tungsten carbide; Wear-resistant coating
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2022.111172

[Display omitted] •The metal-ceramic interaction during the manufacturing of Metal Matrix Composites is thermally driven; thus, it depends on the thermal cycle and process parameters.•In laser-directed energy deposition of Co-base and WC-reinforced Metal Matrix Composites, diffusion and carbide precipitation are revealed by SEM and EDS analysis.•The main strengthening mechanisms of Co-WC Metal Matrix Composites are identified: solid-solution of tungsten and carbide precipitation, or grain refinement.•Statistical regression models are implemented as a tool for data analysis. The prediction of the in-service behaviour of metal-matrix composites produced by laser-directed energy deposition is a fundamental challenge in additive manufacturing. The interaction between the reinforcement phase and the matrix has a major impact on the micro and macroscopic properties of these materials. This interaction is fostered by the exposition of the materials to high temperatures. Hence, it is highly influenced by the thermal cycle of the manufacturing process. In this work, an experimental approach is adopted to determine the influence of the main process parameters on the properties of metal-matrix composites. Statistical regression models are employed to consider the role of the most relevant parameters, from exploration to exploitation. The obtained trends are further corroborated by the corresponding microstructural, SEM, and EDS analyses. In terms of surface hardness, the DOE reveals different trends of the response depending on the composition of the feedstock employed. It is concluded that the strengthening behaviour of the material varies throughout the experimental domain studied. When high WC% feedstocks are employed, the main strengthening mechanism responsible for the increase of hardness is the solid-solution of tungsten and carbide precipitation. On the contrary, when low WC%s are employed, grain refinement becomes the main strengthening mechanism.