Preparation and performance of electrodeposited Ni-TiB2-Sm2O3 composite coatings

Sm2O3 and TiB2 were used as codeposited particles in electrodeposition Ni-TiB2-Sm2O3 composite coatings to improve its performance. Ni-TiB2-Sm2O3 composite coatings were electrodeposited in the nickel sulfate, hexadecylpyridinium bromide and cetyltrimethylammonium bromide solution containing TiB2 and Sm2O3 particles. The content of codeposited Sm2O3 in the composite coating was controlled by changing the concentrations of Sm2O3 particles in the solution. The composite coatings were characterized with X-ray diffraction (XRD) and inductively coupled plasma-atomic emission spectrometer (ICP-AES). The effects of Sm2O3 content on microhardness, wear weight loss and friction coefficient of composite coatings were investigated, respectively. The microhardness of the Ni-TiB2-Sm2O3 composite coatings was 19.35%, 16.58%, 2.03% higher than that of the Ni coating, Ni-Sm2O3 and Ni-TiB2 composite coatings, respectively. The wear weight loss of the Ni-TiB2-Sm2O3 composite coatings was 7, 2.33, 1.22 times lower than that of the Ni coating, Ni-Sm2O3 and Ni-TiB2 composite coatings, respectively. The friction coefficient of the Ni coating, Ni-Sm2O3, Ni-TiB2 and Ni-TiB2-Sm2O3 composite coatings were 0.712, 0.649, 0.850 and 0.788, respectively. The loading-bearing capacity and the wear-reducing effect of the Sm2O3 particles were closely related to the content of Sm2O3 particles in the composite coatings.