Al2O3 thin coating of AA 6082 T6 components using a fast regime fluidized bed

Abstract

Fluidized bed processing is a relatively novel method for coating metal substrates. A detailed study was carried out into surface property and in micro-structure changes induced by fluidized bed processing. In particular, fluidized bed processing of AA 6082 T6 aluminum alloy components using alumina Al 2 O 3 powder was investigated. Firstly, the build up of Al 2 O 3 films was studied and characterized in terms of coating thickness and adhesion. It was found that trends of deposited Al 2 O 3 were consistent with fluidized bed processing time. Secondly, the effect of fluidized bed treatment on surface properties of processed components was examined. Surface morphology was significantly affected and its evolution according to processing time was accounted for. Both compressive residual stresses and increased dislocation density were induced by treatment of external layers of samples, and significant hardening was also detected. Lastly, the ability of fluidized bed processing was tested on Fad hoc' fatigue samples. Rupture of fluidized bed treated samples as well as untreated samples was also discussed. At any rate, the fatigue behavior of processed components significantly improved. This quite new and unprecedented result is ascribed to the compressive residual stresses and work hardening induced by FB treatment in the outermost surface layers of the aluminum alloy. D

Progress in fluidized bed assisted abrasive jet machining (FB-AJM): Internal polishing of aluminium tubes

“…Nevertheless, in employing progressively smaller abrasive size, the average size of splinters embedded in the surface decreased, and consequently, the result has a more aesthetically pleasing appearance. Similar results were found in previous studies of fluidized bed machining, which found widespread embedding phenomena of harder abrasive splinters in the softer substrates are recurrent phenomena (alumina splinters in aluminium and brass substrates [32,33], copper splinters in polyamide 6 and 66 substrates [34]). Fig.…”

Electrostatic spray deposition (ESD) of polymeric powders on thermoplastic (PA66) substrate

“…It is deduced that the copper film already deposited has a self-limiting effect preventing growth of a thicker coating. This mass growth trend and related saturation effect is very similar to that found for low speed cold spray [8] and fast fluidized bed [9] coating process using ceramic powders on metal substrates. Here the rapid increase of film thickness during the initial moments of the coating process was quickly followed by an asymptotic condition [9].…”

“…This mass growth trend and related saturation effect is very similar to that found for low speed cold spray [8] and fast fluidized bed [9] coating process using ceramic powders on metal substrates. Here the rapid increase of film thickness during the initial moments of the coating process was quickly followed by an asymptotic condition [9]. ONCE established, the copper film was found to change the electrical properties of the plastic substrate, making it suitable for electrostatic deposition.…”

On the use of CrN/Cr and CrN interlayers in hot filament chemical vapour deposition (HF-CVD) of diamond films onto WC-Co substrates

“…1). FBP presents significant advantages compared to conventional shot peening as it allows uniform treatments on large surfaces, use of lower operational pressure and longerlasting media, potential for self-regeneration of the diamond media, continuous and easy-to-automate treatments, relatively reduced cost and processing time, low environmental impact and operational safety [31][32].…”