Elektrodepozisyon ile orta karbonlu çeliklerde Ni-B-Co kaplama

The nickel-boron alloy coating has been improved in several engineering fields in recent years due to their high hardness, good corrosion resistance, long durability and suitable solderability as an alternative to hard chrome plating. Due to its superior properties nickel-cobalt based coatings have wide application areas in industrial and technological fields. Coating layers which are used in Micro Electro Mechanical Systems (MEMS) and Nano Electro Magnetic Systems (NEMS) and whose thickness starts from nm level and reaches to mm level according to usage area is needed. The coatings to be produced for these applications require superior mechanical, high abrasion and corrosion resistance, low internal stress and high thermal stability. nickel-cobalt based coatings are good candidates for such applications. In this study, nickel-boron coatings containing trimethylamine borane in different amounts were produced by direct current by using a watt bath on medium-carbon steels, nickel-boron-cobalt alloy coatings containing in fixed amounts of trimethylamine borane and in different amounts of cobalt sulphate were produced by direct current by using a watt bath on medium-carbon steels and also, nickel-boron-cobalt alloy coatings containing in fixed amounts trimethylamine borane and cobalt sulphate were produced by direct current, pulse current and pulse reverse current by using a watts on medium-carbon steels. The resulting coatings are characterized using scanning electron microscope and X-ray diffraction methods. The effect of amount of the trimethylamine borane and cobalt sulphate and current type on the mechanical, tribological and corrosion properties was investigated. The best results for Ni-B alloys as a result of the investigations were obtained with addition of 1.5 g/L trimethylamine borane and the best results for Ni-B-Co alloys were obtained with 1 g/L addition cobalt sulphate and direct current.