Experimental and First Principles Study of the Ni-Ti-W System

• Type: Article in International Scientific Journal
• Date: 2013

Authors

M. H. de Sá (Author) FEUP; I. Isomäki (Author) FEUP; J. A. Ferreira (Author) FEUP; M. Hämäläinen (Author) FEUP; M. H. Braga (Author) FEUP

Journal

Title: Materials Science Forum

Vol. 730-732

Pages: 775-780

ISSN: 0255-5476

Publisher: Trans Tech Publications Ltd

Indexing

ISI Web of Knowledge - 4 Citations

ISI Web of Science

Scopus - 4 Citations

COMPENDEX

INSPEC

Scientific classification

FOS: Natural sciences

Other information

Authenticus ID: P-005-3PX

DOI: 10.4028/www.scientific.net/MSF.730-732.775

Abstract (EN): Nickel based superalloys are structural materials with a chemical composition and structure which has been developed to enable good high temperature performances leading to a wider range of applications. Their unique properties are due to their microstructure characterized by the coexistence of L12-ordered intermetallic precipitates like Ni3Al or Ni3Ti - ¿¿ phase - in a facecentered cubic nickel based solid solution matrix, (Ni) - ¿ phase. Solid solution strengthening at high temperatures can also be provided by the addition of refractory alloying elements, like tungsten, W. Therefore, the mechanical properties behaviour of the alloys is very strongly related to their composition and microstructures. The purpose of this work is to study the effect of composition and microstructures in a series of Ni-rich prototype alloys, Ni100-2x¿Tix¿Wx (in which x is in at.%), in order to understand and ultimately optimize the performance of these materials. The adopted strategy was to combine experimental studies using Neutron Diffraction, Electron Probe Micro Analysis ¿ EPMA, Differential Scanning Calorimeter ¿ DSC and micro-hardness measurements, with first principles calculations for structure optimization and Gibbs energies at different temperatures, for each phase, leading to thermodynamic assessment.

Language: English

Type (Professor's evaluation): Scientific