Preparation and characterisation of nickel-based brazing powder: cobalt and chromium addition effects

ABSTRACT

In the present work, three novel brazing powders were produced, in addition to a commercial composition, by the mechanical alloying (MA) method. Cobalt and chromium’s effects on the properties of brazing powder and related joints were investigated. The results showed that; with the addition of cobalt, the powder morphology went to a rounded and near-spherical shape after 15 milling hours, and the solidus significantly raised. Also, chromium shifted the melting range to higher temperatures. The powder with 6% cobalt and 14% chromium had more than 100°C higher solidus and a melting range of 20°C than the commercial BNi-2, ideal for working temperature of more than 1000°C. The shear strength results revealed that the addition of chromium and cobalt significantly promotes joint strength owing to the activation of the solid solution strengthening mechanism. Therefore, the novel synthesized brazing powders can be an excellent candidate for high temperature and corrosive operating environments.

KEYWORDS:

• Nickel
• powder
• mechanical alloying
• brazing
• superalloy
• fillers
• synthesis
• characterisation

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

E. Hosseini

Emadoddin Hosseini is a master of materials science and engineering from Amirkabir university of technology. He defended his thesis about brazing powders in 2020.

M. Amirjan

Mostafa Amirjan received a Ph.D. degree in Materials Science and Engineering in 2014 from KNTU university of Technology. He is the assistant professor in the Metallurgy research department at Niroo Research Institute (NRI). His main research activities are powder metallurgy/processing, additive manufacturing, and functionalizing the powder materials and processes for several applications.

N. Parvin

Nader Parvin received a Ph.D. degree in powder metallurgy in 1989 from Aston University. He is the associate professor in the faculty of materials and metallurgical engineering at the Amirkabir University of Technology. His main research activities are powder metallurgy/processing, additive manufacturing, and functionalizing the powder materials and processes for several applications.