Interlayer design to control interfacial microstructure and improve mechanical properties of active brazed Invar/SiO2–BN joint

Effects of Cu interlayers on the microstructure and mechanical properties of Al2O3/AgCuTi/Kovar brazed joints

“…It can be seen that intact joints without breaches or defects were obtained. When the thickness of the Cu foil was 50 or 100 μm, the thickness of the brazing seam did not significantly increase compared with the Al 2 O 3 /AgCuTi/Kovar joint, which is consistent with the results found in Refs (). The reason for this was that the addition of Cu improved the wettability of filler resulting in excessive spreading on the surface of the base material.…”

“…Further research also showed that the disappearance of the wave‐like TiFe 2 –TiNi 3 structure had a small effect on joint strength when a AgCuTi + TiNp/Cu/AgCu three‐layered filler was used to braze Si 3 N 4 and Invar alloys . Yang et al designed a type of AgCu/Cu/AgCuTi multi‐interlayer to control the interfacial microstructure and improve the mechanical properties of active brazed Invar/SiO 2 –BN joints. The addition of Cu foil could be used as a barrier layer to inhibit the reaction between Ti in the liquid AgCuTi filler and the elements Fe, Ni dissolved from the alloy so that the amount of TiFe 2 and TiNi 3 formed in the brazing seam decreased and the thickness of the reaction layer increased.…”

“…In addition, a Cu interlayer has high ductility. The plastic deformation of Cu during the solidification process can help decrease the residual stress produced because of the CTE mismatch between the substrates and the filler metal …”

Brazing of ZrB2–SiC–C ceramic and GH99 superalloy to form reticular seam with low residual stress

“…8b, the fracture of Cu foil joints mainly occurs in ZSC adjacent to the reaction layer and away from the braze seam. The fracture morphologies of both direct brazing and Cu foil joints indicate relatively high residual stress concentrations [36]. By contrast, the Cu mesh joint fractures only inside the ZSC ceramic away from the braze seam, which can be seen in Fig.…”

Low-temperature diffusion brazing of actively metallized Al2O3 ceramic tube and 5A05 aluminum alloy

“…The interfacial reactions, microstructure, mechanical properties, and their relationship were studied comprehensively. Furthermore, focus has also been placed on the improvement of joint properties, and the addition of a soft interlayer as well as A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 3 in situ formation of particles or whiskers with a low thermal expansion coefficient (CTE) were demonstrated to be effective methods to realize this improvement [26].…”