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Resistance bonding of dissimilar alloys using a powder interlayer: A feasibility study. / Cameron Pleydell-Pearce

Swansea University Author: Cameron Pleydell-Pearce

Abstract

An experimental framework has been developed that allows investigation of a novel resistance bonding technique incorporating a metal powder interlayer as a means of forming sound joints between dissimilar alloys. Bonds have been produced between Ti- 6AI-4V, Inconel 718 and super CMV steel. Ti-6-4, B...

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Published: 2008
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
URI: https://cronfa.swan.ac.uk/Record/cronfa42467
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Abstract: An experimental framework has been developed that allows investigation of a novel resistance bonding technique incorporating a metal powder interlayer as a means of forming sound joints between dissimilar alloys. Bonds have been produced between Ti- 6AI-4V, Inconel 718 and super CMV steel. Ti-6-4, BurTi and Inconel 718 powder interlayer layers have been trialed. The use of diffusion barrier coatings and transition layers have been explored with particular interest focussed on the effect of tantalum. These trials were then compared to analysis of corresponding bond chemistries produced by a conventional hot isostatic pressing technique. It was found that joints between Ti-6AI-4V and Inconel 718 and super CMV were prone to the formation of intermetallic films at the interface (NiTi, Ti2Ni, Fe2Ti), resulting in poor bond quality. Whilst the use of diffusion barrier layers reduced reaction zone size, tantalum layers in particular were found to severely degrade joint integrity. Bonds produced between Inconel 718 and super CMV performed more encouragingly; achieving around 70% of Inconel 718 parent metal properties in the optimum condition. Comparisons between conventional HIP procedures and resistance bonding elucidated far better powder consolidation in the former. This was shown to be due to a 'differential heating' effect under resistance heating. A quasi isostatic powder interlayer bonding technique (QUIP) has been developed that has shown to substantially improve joint integrity. This is under continuing development.
Keywords: Materials science.
College: College of Engineering