Preparation and performance of electrodeposited Ni-TiB 2-Sm 2O 3 composite coatings

Abstract

Sm 2O 3 and TiB 2 were used as codeposited particles in electrodeposition Ni-TiB 2-Sm 2O 3 composite coatings to improve its performance. Ni-TiB 2-Sm 2O 3 composite coatings were electrodeposited in the nickel sulfate, hexadecylpyridinium bromide and cetyltrimethylammonium bromide solution containing TiB 2 and Sm 2O 3 particles. The content of codeposited Sm 2O 3 in the composite coating was controlled by changing the concentrations of Sm 2O 3 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 Sm 2O 3 content on microhardness, wear weight loss and friction coefficient of composite coatings were investigated, respectively. The microhardness of the Ni-TiB 2-Sm 2O 3 composite coatings was 19.35%, 16.58%, 2.03% higher than that of the Ni coating, Ni-Sm 2O 3 and Ni-TiB 2 composite coatings, respectively. The wear weight loss of the Ni-TiB 2-Sm 2O 3 composite coatings was 7, 2.33, 1.22 times lower than that of the Ni coating, Ni-Sm 2O 3 and Ni-TiB 2 composite coatings, respectively. The friction coefficient of the Ni coating, Ni-Sm 2O 3, Ni-TiB 2 and Ni-TiB 2-Sm 2O 3 composite coatings were 0.712, 0.649, 0.850 and 0.788, respectively. The loading-bearing capacity and the wear-reducing effect of the Sm 2O 3 particles were closely related to the content of Sm 2O 3 particles in the composite coatings.