| Summary: | Heat-treatment is a frequently used technique for modifying the physical and chemical properties of materials. In this study, the effect of heat-treatment on the mechanical properties, thermal stability and surface morphology of two types of electrodeposited coatings (pure-Ni and Ni/Al<sub>2</sub>O<sub>3</sub>) were investigated. The XRD analyses showed that the crystal structure of the as-deposited coating changes from slightly amorphous to crystalline as the heat-treatment temperature increases. The heat-treatment of both the pure-Ni and the Ni/Al<sub>2</sub>O<sub>3</sub> coating caused an increase of the grain size within the coatings. However, the unreinforced Ni coating experienced a faster growth rate than the Ni/Al<sub>2</sub>O<sub>3</sub> coating, which resulted in a larger average grain size. The temperature-driven changes to the microstructure of the coatings caused a reduction in the hardness and wear resistance of the coatings. The presence of nanoparticles within the Ni/Al<sub>2</sub>O<sub>3</sub> coating can successfully extend the operational temperature range of the coating to 473 K by pinning grain boundaries.
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