Microstructure and Strength of gamma-TiAl alloy/Inconel 718 brazed joints

• Tipo: Artigo em Livro de Atas de Conferência Internacional
• Data: 2013

Autores

Sequeiros, EW (Autor) Outra; Guedes, A (Autor) Outra; Pinto, AMP (Autor) Outra; Vieira, MF (Autor) FEUP; Viana, F (Autor) FEUP

Ata de Conferência Internacional

Título: ADVANCED MATERIALS FORUM VI, PTS 1 AND 2

Páginas: 835-840

6th International Materials Symposium (MATERIALS 2011)/15th Meeting of SPM

Guimaraes, PORTUGAL, APR 18-20, 2011

Indexação

ISI Web of Knowledge - 7 Citações

Scopus - 12 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia dos materiais

Outras Informações

ID Authenticus: P-005-3Q2

DOI: 10.4028/www.scientific.net/msf.730-732.835

Abstract (EN): Intermetallics and superalloys brazing development is a current topic owing the extending use of these alloys in industrial applications. In this work a gamma-TiAl alloy was joined to Inconel 718 by active metal brazing, using Incusil-ABA as filler. Joining was performed at 730 degrees C, 830 degrees C and 930 degrees C, with a 10 min dwelling time. The interfaces were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and Electron Backscatter Diffraction (EBSD). For all processing conditions, the reaction between the base materials and the braze alloy produced multilayered interfaces. For all processing temperatures tested (Ag), (Cu), AlNi2Ti and AlCu2Ti were identified at the interface. Raising the brazing temperature increased the thickness of the interface and coarsened its microstructure. The increase of the extension of the interface was essentially due to the growth of the reaction layers formed near each base material, which were found to be mainly composed of intermetallic compounds. The mechanical behavior of the joints, at room temperature, was assessed by microhardness and shear tests. For all processing conditions the hardness decreases from periphery towards the Ag-rich centre of the joints. Brazing at 730 degrees C for 10 min produced the joints with the highest average shear strength (228+/-83 MPa). SEM and EDS analysis of the fracture surfaces revealed that fracture of joints always occurred across the interface, preferentially through the hard layer, essentially composed of AlNi2Ti, resulting from the reaction between Inconel 718 and the braze alloy.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6