**4. Conclusions**

This work presents the results obtained from a study of the effects of both: SiC disper‐ sion in the metallic matrix and thermal treatment on the tribological characteristics (hardness, wear resistance, and coefficient of friction) of electrodeposited Ni-P-SiC coatings.

Our results show that the dispersion of SiC particles in the metallic matrix improves coating tribological properties such as hardness and wear resistance while diminishing the friction coefficient.

The best results were obtained when a current density of 0.042 A/cm2 was used in an electrolytic bath containing 0.02 g mL-1 of SiC. Such conditions produce a metallic matrix with a concentration of 0.52 at.% SiC particles that in turn increase the Ni-P hardness from 430 HV (for the case when SiC particles are absent) to 600 HV. Despite the observed enhancement in hardness, such values are still below those exhibited by hard Cr coatings (1020 HV).

The XRD results indicated that the Ni-P-SiC composites were amorphous in nature. Thermal treatment between 400 °C and 500 °C changed the microstructure of the Ni-P-SiC matrix from amorphous to crystalline. Thermally treating the Ni-P-SiC coatings at temperatures ≥500 °C transformed the amorphous alloy into a continuous Ni3P layer containing isolat‐ ed Ni crystals.

An increased hardness and a decreased wear coefficient were observed after heat treat‐ ment for 60 min at 500 °C because of the formation of a Ni3P phase.

We also observed that the wear volume was inversely proportional to the microhardness of the deposits. As a result, the Ni-P-SiC coatings that were thermally treated at 500 °C possessed the greatest wear resistance; this resistance was superior even to that of hard Cr coatings.
