The production of laminar composite Al-Al2O3
Jerzy Robert Sobiecki*, Piotr Tomassi** *Politechnika Warszawska, Wydział Inżynierii Materiałowej, ul. Wołoska 141, 02-507 Warszawa **Instytut Mechaniki Precyzyjnej, ul. Duchnicka 3, 01-796 Warszawa
Quarterly No. 3, 2006 pages 20-25
DOI:
keywords: electrochemical oxidation, diffusion welding, aluminum, aluminum oxide, laminar composite
abstract The paper presents the results of investigations which are concerned with possibility of obtaining the laminar composite Al-Al2O3 produced by electrochemical oxidation and diffusion welding of samples with produced oxide layers. The combining of these methods leads to create laminar composite in which the aluminum oxide layers are dispersed in the aluminum alloy. The oxide layers produced by electrochemical oxidation significantly improves the corrosion resistance of aluminum (Fig. 3). It has been established that the application of seal after the obtaining the oxide layers does not influence on corrosion resistance but makes impossible to join properly the produced layers. The metallographic (Fig. 4) and chemical composition examinations (Fig. 5) proved that the optimum temperature of welding is 580°C, the pressure is 4 MPa and the time 2 h. The apparatus is shown in Figure 1. These conditions caused the formation of laminar composite with no pores in the joined zone. The decrease of the thickness of oxide layers improves the joining of them by the presence of discontinuity in connecting zone (Fig. 5c). But it must be underlined that the joining the ceramic oxide layers 20 μm thick between themselves succeeded (Figs. 4b and 5b). The attempt of joining four samples with thinner aluminum oxide layers was also effective (Figs. 5b, c).