Effect of Cr on the properties and microstructure of nickel aluminum metal bond

Abstract

Vacuum hot pressing sintering was used to add Cr powders to the nickel aluminum metal bond to improve the mechanical properties of nickel aluminum metal bond. The effects of Cr powder content (molar fraction) and sintering temperature on the mechanical properties and microstructure of the nickel aluminum metal bond were studied. The results show that, Cr plays the role of solid solution strengthening, which can improve the mechanical properties of the nickel aluminum metal bond. As the Cr content increases, the flexural strength of the bond increases first and then decreases, while the Rockwell hardness shows an overall increase tendency at 800 ℃. When Cr molar fraction is 12%, the optimal flexural strength and Rockwell hardness are 178 MPa and HRB 104.2, respectively, which are increased by 36.9% and 6.8% compared with the pure nickel aluminum metal bond.

Keywords

• metal bond
• cr doping
• microstructure
• mechanical properties
• phase composition