Speaker
Description
This study presents the development and optimization of a novel hybrid wire–powder Plasma Arc Directed Energy Deposition (DED) process for the fabrication of metal matrix composites (MMCs). The system integrates an auxiliary powder feeder into a conventional wire-based plasma DED setup, enabling the simultaneous deposition of a mild steel wire matrix and TiC ceramic powder reinforcement.
A design of experiments (DOE) was performed to optimize key powder feeding parameters, including carrier gas flow rate and nozzle diameter, using single-track depositions. Low-carbon steel was used as the substrate and wire (matrix) material, while TiC powder was used as the reinforcement particles. The optimized parameters were subsequently applied to fabricate multi-layer wall structures with varying TiC reinforcement contents under different thermal conditions, both with and without substrate preheating.
Metallographic analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and image-based density measurements were used to evaluate reinforcement distribution, defect formation, interface quality, and TiC retention. Depositions without preheating exhibited cracking, porosity, and particle agglomeration resulting from steep thermal gradients. Substrate preheating significantly improved particle distribution and reduced cracking and porosity by lowering thermal stresses. Furthermore, a layer-staggering strategy comprising four hybrid layers followed by a single wire-only layer improved wall integrity by mitigating residual stress.
The results demonstrate the feasibility of hybrid wire–powder Plasma Arc DED for MMC fabrication and identify thermal management and reinforcement distribution strategies as critical factors for achieving defect-free multi-layer structures. The successful integration of wire and powder feedstocks within a single Plasma Arc DED process represents a significant step toward flexible, compositionally tailored, and functionally graded MMC manufacturing, unlocking new possibilities for advanced engineering applications.
| Speaker Country | Germany |
|---|---|
| Would you like to publish your paper in the special issue of BHM "Berg- und Hüttenmännische Monatshefte" | No |