Enhancing Ni electroplated matrix through mixed boron nitride–carbide reinforcement

Autor: V. Mozafari, A. Jafari, M.E. Bahrololoom, S. Paydar
Rok vydání: 2013
Předmět:
Zdroj: Vacuum. 92:52-57
ISSN: 0042-207X
DOI: 10.1016/j.vacuum.2012.10.014
Popis: Mixed Nitride–Carbide particles of boron as a reinforcement in Ni matrix has been used in an attempt to form three component composites of superior hardness. The colloidal form of the dispersed particles has pronounced effect on distribution of the particles and this can be traced back to their zeta potential which governs the agglomeration propensity of the particulates with direct bearing on hardness and resultant morphology. Specific steps must be taken for Ni–BN–B 4 C formation and simultaneous deposition of two dissimilar compounds and thus getting the desired volume fraction of each in the coating. Copper as a well understood system when it comes to nickel plating was utilized as the substrate and Watts plating bath admixed with 1–10 g BN and 10–50 g B 4 C powder at 30–60 mA/cm 2 was employed. To compare results without the possibility of elastic rebound effects from the substrate all experiments were performed on 50 micron thick composite layers. Microhardness and scanning electron microscope (SEM), X-ray diffraction (XRD), optical microscopy (OM) techniques were used to ascertain the role and advantages gained from co-deposition of mixed reinforcing powders and the overall conclusion was that superiority of such composites in strengthening hardness relies heavily on the regular and controlled distribution of the particulates.
Databáze: OpenAIRE
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