Diffusion brazing repair of IN738 superalloy with crack-like defect: microstructure and tensile properties at high temperatures. (2nd January 2019)

• Record Type: Journal Article
• Authors: Ye, Y.; Zou, G.; Long, W.; Jia, Q.; Bai, H.; Wu, A.; Liu, L.
• Is Part Of: Science and technology of welding & joining. Volume 24:Number 1(2019)
• Page Start: 52
• Page End: 62
• Publication Date: 2019-01-02
• Subjects: Superalloy -- post heat treatment -- tensile strength -- microstructure; Welding -- Periodicals; Joints (Engineering) -- Periodicals; Surfaces (Technology) -- Periodicals; 671.52
• DOI: 10.1080/13621718.2018.1477546
• Languages: English
• ISSNs: 1743-2936

Abstract

ABSTRACT: In this study, tapered slots with an opening width about 200 μm were artificially fabricated in IN738LC superalloy to imitate service cracks. The 'cracks' were repaired by diffusion brazing with a Ni–Cr–Co–Al–Ta–B filler alloy at 1150°C and then heat treated at 1180°C (HT-A) and 1190°C (HT-B), respectively. A joint with uniform microstructure, chemical composition and hardness was obtained using HT-B. The mechanisms of the borides evolution during homogenisation were discussed. The tensile strength of the HT-B joint tested at 20, 600 and 800°C reached up to approximately 96, 90 and 87% of the base metal, respectively. The fracture modes of the joints tensile tested at various temperatures were discussed.