tA serious number of critical aspects have to be considered when aluminium and its alloys, especiallyif heat treated, are welded. These drawbacks, to date, limit the application of the welded joints in theaeronautical sector. The possibility of overcoming these limitations is focused in current paper by study-ing the mechanical performance of two types of dissimilar laser beam welds in T-joint configuration.The dissimilar joints, planned for aeronautical applications, combine the same skin, made of AA 6156alloy, with two different base materials for the stringers, namely the AA 2139 and the non-standard alloyPA765. The alloys under investigation are characterized by enhanced weldability if compared to the stan-dard AA 2024, widely used in aeronautic. Due to the contemporary presence of dissimilar heat treatablealuminium alloys, both joints have been subjected to dedicated multi-step heat treatments.Metallurgical and microstructural analysis were carried out in order to highlight the influence of bothchemical composition and thermal cycles experienced on the final microstructures of different zones ofthe joints, governing the mechanical properties of the joint itself.Vickers micro-hardness measurements were performed to fully characterize the heterogeneity inmechanical properties across the different zones of the dissimilar welds. Strain data acquisition by Digi-tal Image Correlation (DIC) allowed to assess the influence of local weld properties on joints strength intensile loading. The important role of the temper conditions of the parent materials, resulting from thedifferent joint pre and post-welding heat treatment options, on the tensile behaviour of the skin and, inthis way, on the global strength of the connection was showed. The dramatic role played by the HeatAffected Zone and the influence of the distribution of the strengthening elements on examined jointsmechanical properties has been put in evidence, according to mechanical test results.
Laser beam welded joints of dissimilar heat treatable aluminium alloys / Viscusi, Antonio; Leitão, C.; Rodrigues, D. M.; Scherillo, Fabio; Squillace, Antonino; Carrino, Luigi. - In: JOURNAL OF MATERIALS PROCESSING TECHNOLOGY. - ISSN 0924-0136. - 236:(2016), pp. 48-55. [10.1016/j.jmatprotec.2016.05.006]
Laser beam welded joints of dissimilar heat treatable aluminium alloys
VISCUSI, ANTONIO;SCHERILLO, Fabio;SQUILLACE, ANTONINO;CARRINO, LUIGI
2016
Abstract
tA serious number of critical aspects have to be considered when aluminium and its alloys, especiallyif heat treated, are welded. These drawbacks, to date, limit the application of the welded joints in theaeronautical sector. The possibility of overcoming these limitations is focused in current paper by study-ing the mechanical performance of two types of dissimilar laser beam welds in T-joint configuration.The dissimilar joints, planned for aeronautical applications, combine the same skin, made of AA 6156alloy, with two different base materials for the stringers, namely the AA 2139 and the non-standard alloyPA765. The alloys under investigation are characterized by enhanced weldability if compared to the stan-dard AA 2024, widely used in aeronautic. Due to the contemporary presence of dissimilar heat treatablealuminium alloys, both joints have been subjected to dedicated multi-step heat treatments.Metallurgical and microstructural analysis were carried out in order to highlight the influence of bothchemical composition and thermal cycles experienced on the final microstructures of different zones ofthe joints, governing the mechanical properties of the joint itself.Vickers micro-hardness measurements were performed to fully characterize the heterogeneity inmechanical properties across the different zones of the dissimilar welds. Strain data acquisition by Digi-tal Image Correlation (DIC) allowed to assess the influence of local weld properties on joints strength intensile loading. The important role of the temper conditions of the parent materials, resulting from thedifferent joint pre and post-welding heat treatment options, on the tensile behaviour of the skin and, inthis way, on the global strength of the connection was showed. The dramatic role played by the HeatAffected Zone and the influence of the distribution of the strengthening elements on examined jointsmechanical properties has been put in evidence, according to mechanical test results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
