Microstructure of Reaction Zone Formed During Diffusion Bonding of TiAl with Ni/Al Multilayer

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Sónia Simões (Author) FEUP; Filomena Viana (Author) FEUP; Mustafa Koçak (Author) Other; A. Sofia Ramos (Author) Other; M. Teresa Vieira (Author) Other; Manuel F. Vieira (Author) FEUP

Journal

Title: Journal of Materials Engineering and Performance

Vol. 21 No. 11

Pages: 678-682

ISSN: 1059-9495

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 26 Citations

Scopus - 31 Citations

INSPEC

Scientific classification

FOS: Engineering and technology > Materials engineering

CORDIS: Technological sciences > Engineering

Other information

Authenticus ID: P-002-AM6

DOI: 10.1007/s11665-012-0144-0

Abstract (EN): In this article, the characterization of the interfacial structure of diffusion bonding a TiAl alloy is presented. The joining surfaces were modified by Ni/Al reactive multilayer deposition as an alternative approach to conventional diffusion bonding. TiAl substrates were coated with alternated Ni and Al nanolayers. The nanolayers were deposited by dc magnetron sputtering with 14 nm of period (bilayer thickness). Joining experiments were performed at 900 A degrees C for 30 and 60 min with a pressure of 5 MPa. Cross sections of the joints were prepared for characterization of their interfaces by scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), high resolution TEM (HRTEM), energy dispersive x-ray spectroscopy (EDS), and electron backscatter diffraction (EBSD). Several intermetallic compounds form at the interface, assuring the bonding of the TiAl. The interface can be divided into three distinct zones: zone 1 exhibits elongated nanograins, very small equiaxed grains are observed in zone 2, while zone 3 has larger equiaxed grains. EBSD analysis reveals that zone 1 corresponds to the intermetallic Al2NiTi and AlNiTi, and zones 2 and 3 to NiAl.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5