Electroless deposition of Ni-P/NANO-Al2O3 composite coatings on PET and carbon fibres substrates
Anna Sałacińska, Jerzy Bieliński, Milena Zawadowska, Rafał Kozera, Anna Boczkowska, Krzysztof J. Kurzydłowski
Quarterly No. 2, 2012 pages 86-92
DOI:
keywords: electroless composite deposition, Ni-P/Al2O3 composite, deposition rate and microstructure, PET and carbon fibres metallization
abstract This paper presents the results of studies on the electroless deposition of Ni-P/nano-Al2O3 composite coatings on pretreated polymeric bases (PET polyester Mylar A type) and on carbon fibres (24k fibres with 7 µm Tenax rovings). The Ni-P matrix was deposited from a solution consisting of NiSO4 0.1 M; NaH2PO2 0.2 M; glycine 0.21 M, with a pH = 7.5÷8.5 and thiourea added as a stabilizer, as well as cetyltrimethylammonium bromide as a surfactant. Aluminium oxide C (DNC - Degussa, grains 13 nm) or A16 (Alcoa, grains 400 nm) were powders amounting to 10÷30 g/l, with ultrasonic homogenization of the suspension. Under the experimental conditions applied, partial sedimentation of the A16 powder occurred, thus a further study on carbon fibres metallization was performed with the use of the DNC nanopowder. Deposition was performed in the temperature range 60÷70oC, during 5÷60 minutes, while the bases rotated at 1 rpm and the suspension was agitated with a stirrer. The composition of the deposited layers was determined by chemical methods and their surface morphology was investigated using SEM. A procedure for the preparation of the PET substrates for the tests was set out to obtain good adhesion of the Ni-P layers. Under the applied conditions, Ni-P/Al2O3 layers of a thickness within 130÷720 nm, aluminium oxide content up to 25% by weight, and 2÷4% phosphorus by weight were obtained.