The trade-off between wear and corrosion performance in WC/W2C reinforced laser powder bed fusion duplex stainless steel composites

The broader application of laser powder bed fusion (LPBF) processed 2205 duplex stainless steel (DSS) is often limited by its wear resistance and pitting corrosion performance. To address this, two types of WC/W 2 C reinforcing particles—small irregular (1–15 μm) and large spherical (15–45 μm)—were incorporated into the 2205 DSS matrix via LPBF. The distinct dissolution behaviors of these particles dictated the resultant properties. Small angular particles underwent complete dissolution, leading to pronounced solid solution strengthening which enhanced corrosion and wear resistance. This composite achieved a hardness increase of over 40 HV 0.5 , a polarization resistance > 0.8 × 10 5 Ω·cm 2 , and a critical pitting temperature (CPT) elevation of > 5 °C, alongside improved wear resistance (reduced wear depth > 5 μm). In contrast, the large spherical particles only partially dissolved, forming micro-galvanic cells with the matrix that severely degraded pitting corrosion resistance, reducing the CPT by 10 °C, despite offering superior wear performance. This study reveals a critical wear-corrosion performance trade-off in LPBF fabricated composites, governed by the dissolution dynamics and morphology of the reinforcing particles.