Mechanism and Performance Characterization of Heat Treatment on Laser-Cladded Ni-WC Coatings

To enhance the wear resistance of laser-cladded Ni-WC coatings, recrystallization and stress-relief annealing treatments were applied. The effects of different annealing treatments on the friction performance of the coatings were analyzed using XRD, SEM, and a friction wear tester. The results showed that recrystallization annealing refined the grains and transformed the Ni4B3 phase, with the lowest crack rate (10.1%) observed at 800 degrees C. Stress-relief annealing effectively released residual stress, achieving the lowest crack rate (6.3%) at 500 degrees C, while promoting the transformation of the Cr7C3 phase and improving coating stability. Furthermore, recrystallization annealing was more suitable for enhancing wear resistance, as the coating treated at 800 degrees C exhibited a lower friction coefficient (0.46) and the smallest wear volume (0.351 mm3). In contrast, stress-relief annealing was more effective in improving hardness, with the coating treated at 500 degrees C achieving the highest microhardness (936.54 HV1).