C/SiC composite-Ti6Al4V joints brazed with negative thermal expansion ZrP2WO12 nanoparticle reinforced AgCu alloy.

Abstract Brazing C/SiC composites to Ti6Al4V alloy is associated with the problem of high residual stress inducing low joining strength. To overcome this problem, negative thermal expansion Zr 2 P 2 WO 12 (ZWP) nanoparticles were introduced into AgCu brazing alloy to obtain robust C/SiC-Ti6Al4V joints. Microstructures and mechanical properties of the joints brazed with different ZWP contents were investigated. Results indicated that 3 wt% ZWP nanoparticles dispersed homogeneously among brazing seam and compatible with brazing alloy. The width of reaction layer at C/SiC side was reduced sharply. Meanwhile, the finite element analysis showed that residual stress was reduced by 52.9 MPa and stress concentration among reaction layer was eliminated. The average shear strength of the joints brazed with AgCu + 3 wt% ZWP increased to 146.2 MPa, which was 70.8% higher than that of joints brazed without ZWP. [ABSTRACT FROM AUTHOR]