EFFECT OF HEAT TREATMENT AND BATH COMPOSITION OF ELECTROLESS NICKEL-PLATING ON CAVITATION EROSION RESISTANCE | ||||
JES. Journal of Engineering Sciences | ||||
Article 17, Volume 41, No 5, September and October 2013, Page 1989-2011 PDF (995.05 K) | ||||
Document Type: Research Paper | ||||
DOI: 10.21608/jesaun.2013.114930 | ||||
View on SCiNiTO | ||||
Authors | ||||
S. A. Karrab 1; M. A. Doheim1; Mohammed S. Aboraia1; S.M. Ahmed2 | ||||
1Mining and Metallurgical Engineering Department, Assiut University, Assiut 71516, Egypt | ||||
2Mechanical Engineering Department, Majmaah University, SA | ||||
Abstract | ||||
Electroless Nickel-Phosphorus coatings have had a lot of interest in various industries due to outstanding characteristics. Some of the highlighted characteristics of electroless Ni-P coatings are superior corrosion and wear resistance. But the effectiveness of electroless Ni-P coating in resisting cavitation damage is not studied so well and is not so clear. In the present investigation, electroless Ni-P coatings were prepared at various conditions including the type of bath, heat treatment temperature and plating solutions composition. The properties of electroless Ni-P coatings were characterized using X-ray diffraction technique (XRD), energy dispersive X- ray (EDX) optical microscope, and microhardness tester. The cavitation erosion tests were carried out to study the effect bath type, heat treatment temperature and plating solutions composition on the deposit coatings. The XRD results indicate that the as-deposit had crystalline structure for alkaline bath and amorphous structure for acid bath. Heat treatment of the coatings produced mixture of polycrystalline phases. The thickness of deposit films depend on the bath type and concentration and were the least for alkaline baths. Maximum hardness of heat treated samples was found to depend on the solution composition and occurs at temperature 300 °C and 400°C. The highest erosion resistance of the coatings was observed for the heat treated deposits at temperature of 650 °C, and comes to the fore the coatings formed in alkaline baths followed by that formed in acid baths. The best erosion resistance for deposits formed in alkaline baths is attributed to the small thickness and crystalline structure. The results showed also that the cavitation erosion resistance is independent on surface hardness. | ||||
Keywords | ||||
Electroless Ni- P coatings; Heat treatment; Cavitation erosion | ||||
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