DEPOSITING Ni–Co–P ALLOY COATING ON AISI316 STEEL AND ANALYZING ITS PROPERTIES

Abstract

After appropriately preparing the surface of AISI316 steel, the Ni–Co–P coating layer was deposited on the substrate using the electroless method using baths with different mole ratios of CoSO4/NiSO[Formula: see text]. Coating rate, weight percentage of the alloy elements, corrosion rate and coating layer hardness were studied in the achieved coating layers. The coating rate of the Ni–Co–P coating layer is a function of the mole ratio of CoSO4/CoSO[Formula: see text], sodium hypophosphite concentration, bath temperature, bath pH and plating time. The electroless deposits studied in this paper are in crystal form. The XRD pattern of the Ni–Co–P deposits shows the peaks related to Ni-fcc and tetragonal Ni[Formula: see text]P5. X-ray diffraction pattern confirms the formation of the Ni3P phase during annealing for 1[Formula: see text]h at 400∘C.

Electroless coating technology for 1060 aluminum alloy and the effect of tin chloride and ‎polymer addition

“…Meanwhile, Ni-P films with low phosphorus content (3-5% P) have good corrosion resistance in concentrated sodium hydroxide solution, and Ni-P alloys with medium or high phosphorus content have excellent corrosion resistance in acidic solutions and in chloride medium [5,12,13]. Typically, to improve the qualities of the electroless binary Ni-P alloy, ternary Ni alloys were created using the codeposition technology of Ni to give the ternary alloys, such as Ni -W -P [14,15], Ni -P -B [16][17][18], Ni -Fe -P [19][20][21], Ni -Cu -P [22][23][24][25], Ni -Co -P [26][27][28][29], Ni -Sn -P [30][31][32][33][34][35] and Ni For instance, studies have found that Ni -Sn -P alloys with low Sn content have good corrosion resistance. However, the majority of the work on Ni-based alloys was done at higher temperatures, such as 80-95 °C [36].…”