This study by Liu, S et al. investigates the application of a Ni-Fe-Cr alloy brazing method to increase the bond strength between WC-Co and low-carbon steel (LCS). The process was conducted in a furnace at 1180°C under an argon atmosphere.

Research Findings:

Bonding and Mechanical Properties:

• XRD, SEM, and EPMA analyses were conducted to examine the WC-Co/LCS interface, confirming the absence of cracks or pores and ensuring a strong metallurgical bond.
• The shear strength of the bonded material was measured to be approximately 321-328 MPa, showing a significant improvement compared to values obtained using Ag-Cu-Zn-Cd, Cu-Zn, Cu-Ni-Al, Ag-Cu-Zn + Ni/Mn, and Ag-Cu-In-Ti filler materials.

Diffusion and Phase Transformations:

• EPMA analyses revealed that Fe, Cr, and Ni diffused from the Ni-Fe-Cr alloy into WC-Co, with distances of 802-815 µm, 803-817 µm, and 632-641 µm, respectively.
• Initially, WIC formed at the sharp corners of WC, which then reacted with Fe and Cr to form M6C and M7C3 phases.

Industrial Applications:

• This method was applied in the production of cylinder sleeves for vertical mills, resulting in a 1.9 times increase in the service life of these parts.

For a detailed review, you can access the related study here.