Effects of Superplastic Deformation on the Diffusion Welding of SuperDux 65 Stainless Steel
Journal
Welding Journal (Miami, Fla)
Journal Volume
78
Journal Issue
9
Pages
301s-304s
Date Issued
1999
Author(s)
Abstract
The SuperDux 651 stainless steel diffusion welded in a nonsuperplastic state (880°C, 60 min) required greater pressure, compared to aluminum and titanium alloys, to create a contact area at the weld interface, which will increase the atomic diffusion paths. However, an unsatisfactory weld strength of 45.3 MPa was obtained under the applied pressure of 7 MPa. This alloy deformed easily at its superplastic temperature of 970°C, resulting in a tight contact surface. The higher welding temperature was also beneficial for atomic diffusion. Both effects were advantageous for diffusion welding, while the joined workpieces macroscopically deformed markedly. In this study, a two-stage diffusion welding method was proposed. The specimens were diffusion welded in a nonsuperplastic (or superplastic) state for a short time and then further diffusion welded at superplastic (or nonsuperplastic) temperatures for a longer heating period. It was found that the welding strength could be improved drastically using such a two-stage process. The contributions of superplastic deformation on the diffusion welding of this alloy during the two-stage process were clarified.
Subjects
Diffusion welding; Shear strength; Stainless steel; SuperDux 65; Superplastic
Type
journal article