Effect of brazing temperature and holding time on joint properties of induction brazed WC-Co/carbon steel using Ag-based alloy

• Published in: Journal of materials processing technology 2016-03, Vol.229, p.562-569
• Main Authors: Jiang, Chao, Chen, Hui, Wang, Qiuying, Li, Yuanxing
• Format: Article
• Language: English
• Subjects: Ag-based alloys; Brazed joints; Brazing; Cemented carbides; Chromium molybdenum steels; Cobalt; Dispersion strengthening; Induction brazing; Shear strength; Silver base alloys; Strengthening; Tungsten carbide; WC-Co/steel joints
• ISSN: 0924-0136
• DOI: 10.1016/j.jmatprotec.2015.09.044

Because of insufficient understanding of the strengthening effect of α-Cu (s.s) in WC-Co/interlayer/35CrMo joints, this research focused on revealing the evolution and strengthening effect of α-Cu (s.s) with brazing temperature and holding time. The joints were performed by high-frequency induction brazing using an Ag-based alloy (Ag-16Cu-23Zn-7.5Mn-4.5Ni, wt.%) as the filler metal. Island-like α-Cu solid solution (s.s) phases widely spread in the filler metal and played a role of dispersion strengthening because of the high hardness. Because of the high affinity between Ni, Co and Fe, α-Cu (s.s) layers formed at the interfaces and strengthened them. The joint strength increased with widening α-Cu (s.s) layers. With increasing brazing temperature and holding time, the total area and number of island-like α-Cu (s.s) phases decreased, contributing to weakening the dispersion strengthening effect. The maximum shear strength of brazed joints was 366MPa when brazing at 770°C for 30s.