On the occurrence of liquation during linear friction welding of Ni-based superalloys

Masoumi, F., Shahriari, D., Jahazi, M., Cormier, J. and Flipo, B. C. D.. 2017. « On the occurrence of liquation during linear friction welding of Ni-based superalloys ». Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, vol. 48A, nº 6. pp. 2886-2899.
Compte des citations dans Scopus : 18.

PDF Jahazi M 2017 15032 On the Occurrence of Liquation During.pdf - Accepted Version Restricted access to Repository staff only Use licence: All rights reserved to copyright holder. Download (2MB)

Abstract

A combination of experimental and analytical methods was used to study the possible occurrence of liquation during LFW of the newly developed AD730TM Ni-based superalloy. LFWed joints were produced using a semi-industrial size facility and the interfaces of the joints as well as the ejected flash were examined using optical and Field Emission Gun Scanning Electron Microscopy (FEG-SEM). Physical simulation of the LFW thermal cycle, using thermomechanical simulator Gleeble™ 3800, showed that incipient melting started from 1473 K (1200 °C). The analytical model, calibrated by experiments, predicted that the highest temperature of the interface was about 1523 K (1250 °C). The constitutive equations based on lattice and pipe diffusion models were developed to quantify the self-diffusivity of the elements and control the extent of liquation by considering the effect of LFW process parameters. Analytical results show that the application of compressive stresses during LFW results in 25 times increase in the diffusion of Ni atoms at the weld interface. Therefore, no presence of re-solidified phases, i.e., occurrence of liquation, was observed in the microstructure of the weld zone or the flash in the present study. Based on the obtained results, a methodology was developed for designing the optimum pressure above which no liquation, and hence cracking, will be observable.

Item Type:	Peer reviewed article published in a journal
Professor:	Professor Jahazi, Mohammad
Affiliation:	Génie mécanique
Date Deposited:	11 Apr 2017 14:00
Last Modified:	13 Apr 2023 16:08
URI:	https://espace2.etsmtl.ca/id/eprint/15032

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