Improving the Fatigue Crack Propagation Resistance and Damage Tolerance of 2524-T3 Alloy with Amorphous Electroless Ni-P Coating

摘要

The surface microhardness, as well as the fatigue crack propagation (FCP) resistance of 2524-T3 alloy, is improved by producing a 20-mu m-thick amorphous electroless Ni-12% P coating on its surface. Compared to the substrate, this deposited EN coating possesses higher strength properties and exhibits a greater ability of accommodating the plastic deformation at the fatigue crack tip, thereby remarkably improving the FCP resistance in near-threshold and early Paris regimes. Regardless of the similar FCP rates in Paris regime (Delta K = 16.2 MPa m(0.5)), the coated sample exhibits extended Paris regime and enhanced damage tolerance.