Microstructure and mechanical properties of vacuum brazing joint between Ni3Al-based alloy IC6 and wrought superalloys GH3030

Two Ni-based filler metals VPR24 and GHL-6-2 used to produce Ni-based superalloys blades and vanes were used on vacuum barzing between alloy IC6 and wrought superalloys GH3030. The microstructures of bonding seam and base metal nearby were observed, and endurance life at 900°C was tested. The results show that VPR24 has no significant effect on the microstructure of the base metal near the bonding seam. Due to a high borocic content in GHL-6-2, much acerose borides bring a bad effect on the properties of the joint precipitate in the base metal next to the bonding seam. The 900°C, 22 MPa stress rupture life of joint using GHL-6-2 is 73 h while that of the joint using VPR24 is 361 h. The joint using VPR24 finally breaks in the base metal GH3030. This indicates that the endurance of the joint is better than that of the base metal GH3030.