Vat photopolymerization of WC-316 L steel-bonded hardmetals with complex structures

Steel-bonded hardmetals, composites comprising hard ceramic phases within a steel matrix, offer excellent wear resistance crucial for demanding applications. However, using traditional processes to fabricate parts with complicated geometry continues to be difficult. This work shows that complex WC-316 L steel-bonded hardmetal components can be produced using vat photopolymerization (VPP) additive manufacturing. An acidic block copolymer dispersant (P5398, 3 wt%) was found to be the best option after a methodical optimization of the photocurable slurry. This resulted in a low viscosity of 4.79 Pa·s at 100 s −1 and improved stability for a 50 vol% solids loading slurry. Specimens were successfully created using optimized printing parameters (95% laser power, 1000 mm/s scan speed, 0.02 mm hatch spacing) and a customized thermal debinding-sintering profile. Samples from the 50% slurry had minimal surface roughness (Ra = 2.34 μm), a transverse rupture strength of 1173.07 MPa, a Vickers hardness of 794.41 HV, and a relative density of 97.3%. WC particles were uniformly distributed throughout the steel matrix, according to microstructural studies, which contributed to the improved mechanical qualities. This work bridges the gap between geometric freedom and material performance by establishing VPP as a practical and accurate manufacturing route for complexly formed, high-performance steel-bonded hardmetals.