The effect of deposition parameters on the thickness distribution in composite coatings obtained by the brush plating method
Jarosław Grześ Politechnika Warszawska, Instytut Technologii Materiałowych, ul. Narbutta 85, 02-524 Warszawa, Poland
Quarterly No. 3, 2008 pages 291-295
DOI:
keywords: brush plating, coatings, composites
abstract This paper presents the investigation results of the effect of selected parameters on the thickness distribution of composite Cu+Al2O3 layers. The investigated layers have been deposited by the brush plating method. The brush plating technique belongs to the bath plating methods of surface coating, but has several advantages which the most important are shorter deposition time (10-20), lower processing costs (materials and energy), easier operation of the deposition equipment, mobility, no limits of the workpiece size, possibility to deposit both on metal and non-metal substrates. The application field for this method is relatively wide. This method can be applied for the repair and regeneration of machine parts and surface modification and for the dimension and geometric form build-up of the machine parts. The brush plating can also be applied to deposit intermediate layers and composite coatings. The main parameters of this process are the operating voltage and the relative moving speed of the tampon. The number of available solutions reaches almost 250, which allows producing single and multilayer coatings with desired properties. The Copper Alkaline #1 solution with Al2O3 (80 nm) nanopowder addition have been utilized during the coating process. The quantity of Al2O3 nanopowder in the plating solution was 30 g/l. The plating solutions used for the deposition have been prepared just before use. Different operating voltages and plating times have been tested. The surface of the substrate has been prepared by a standard procedure included electrocleaning, activating and covering with a special Ni sublayer. The coatings were deposited by using DSQ-15 brush plating system. The typical ZDB-V stylus electrode handles and metal anodes (4 mm diameter) were used for the deposition. The conducted investigation also covered the basic microscopic analysis of the surfaces and cross-sections of obtained coatings as well as the thickness measurements. The results obtained from the experiment have shown good adhesion of the Cu+Al2O3 layers to the substrate with no cracks observed in the Cu+Al2O3 coatings. The thickness measurements have been conducted in 21 points. The analysis of the results has shown an increase of the average thickness of the layers, its standard deviation and the changes of its growth with increasing of the voltage and plating time. The most intensive deposition have been observed in places of tampon movement changes.