Dual-scale WC particle-reinforced 316 alloy fabricated via Laser-directed energy deposition: Mechanical and electrochemical Properties

An innovative approach for reinforcing 316L alloy with WC particles of different scales is proposed. WC/316L composite specimens featuring single- and multi-layer structures with different WC particle scales were produced through the laser-directed energy deposition (LDED) process. The incorporation of WC effectively promoted the formation of a passive film, significantly impeding the penetration of Cl ⁻ ions from the NaCl solution into the composite, thus preventing charge transfer and effectively suppressing further corrosion. Among the specimens, the fine WC/316L composite showed the highest corrosion resistance, achieving an 83.54% reduction in corrosion current and a 724.5% increase in polarization resistance. The average transverse tensile strengths for the four specimens—316L, 8 wt.% coarse WC/316L, 8 wt.% fine WC/316L, and a combination of 4 wt.% coarse WC and 4 wt.% fine WC/316L—were measured at 916 MPa, 959 MPa, 977 MPa, and 929 MPa, respectively, at three tensile rates. Compared to the pure 316L specimen, the tensile strengths of the other three materials improved by 4.7%, 6.7%, and 1.4%, respectively. These results demonstrate that the incorporation of WC significantly enhances the corrosion resistance and tensile properties of 316L alloy, offering an innovative solution to challenges like corrosion vulnerability and limited strength in aerospace, petroleum, and other applications.