Optimization of WLAM process Parameters for Metal Forming Tool Repair
Résumé
Tool wear in metal forming leads to a drop in product quality and non-compliance with initial specifications. Tools exhibiting noticeable wear are typically replaced, incurring additional costs and environmental concerns. With the advent of the metallic additive manufacturing, there is now the possibility of repairing tools instead of outright replacement. This innovative approach can be applied in metal forming processes to locally add melted materials, effectively repairing forming tools. It is obviously crucial that the repaired tool possesses the same or better tribological properties than the initial tool, otherwise the benefit of repairing tool will be lost due to poor tribological properties.
In this study, a wire laser additive manufacturing system, equipped with a six-beam direct diode laser head, is involved to repair worn surfaces of metal forming tool. The study focusses on the influence of process parameters on the behaviour of the weld bead and substrate. a particular attention is paid on the effect of the impact of energy density on the hardness, microstructure, dimensional stability, and the penetration of weld beads into the substrate.
Preliminary results show that optimal morphological stability and homogeneity of the weld bead are achieved at an energy density greater than 100 J/mm3. The friction tests show a good response of the reloaded tool in terms of substrate/weld bead adhesion and friction coefficient. However, the friction coefficient remains high compared to the initial tool. And a large heat-affected zone (HAZ), with a martensitic structure, is generated under the weld bead. Future tests will focus on improving tribological properties and reducing HAZ hardness.
Origine | Fichiers produits par l'(les) auteur(s) |
---|---|
Licence |
Copyright (Tous droits réservés)
|