Strength optimization of two-step-bonded Ti-6Al-4V/Si3N4 joint with Nb interlayer via transient-liquid-phase bonding and active-metal brazing

A novel two-step bonding of Ti-6Al-4V/Si 3 N 4 joint was developed with Nb interlayer as residual-stress reliever via low-pressure transient-liquid-phase (TLPB) Ti-6Al-4V/Nb side prior to active-metal brazing Nb/Si side. While 1.75 mass% Ti in a 50-µm-thick CUSIL-ABA® filler sufficient for sound at when brazed 1103 K 10 min, one-step-brazed joints area × mm 2 were prone failure the due brittle Cu-Ti intermetallic compounds (IMCs). Replacing TLPB using pure Cu and Ni foils 1213 180 min eliminated formation IMCs homogenization (? + ?)-Ti; bending strength increased 193 MPa residual-stress-induced from Si ceramics. Finally, effectiveness stress-accommodation filler’s plastic flow quantitatively verified reasonable fidelity by finite-element analysis incorporating temperature-dependent elasto-plastic properties. • Robust dissimilar brazing. Optimization content temperature Low-pressure Ti-6Al-4V fillers. Estimation finite-element-analyzed thermal residual stress.