Brazing of SiC ceramics pretreated by chromium coating using inactive AgCu filler metal

Abstract

In this work, chromium coating conducted by magnetron sputtering was introduced to braze SiC ceramics using inactive AgCu filler metal. The results showed that reliable metallurgical bonding of SiC ceramics was obtained at 900°C for 10 minutes. SEM, XRD, and TEM were used to identify the reaction phase in the joint, and the typical interfacial microstructure was SiC/mixed CrSi 2 + Cr 23 C 6 layer/CrSi 2 / Ag(s,s)+Cu(s,s)/CrSi 2 /mixed CrSi 2 + Cr 23 C 6 layer/SiC. The shear strength of SiC joint using chromium coating brazed with inactive AgCu filler metal was 29.6 MPa and the joint fractured at the SiC substrate entirely after shear test. The proposed active element coating method provides a feasible way to achieve the brazing of ceramics.

Joining of Cf/SiC composites using AlCoCrFeNi2.1 eutectic high‐entropy alloy filler by spark plasma sintering

“…The enrichment of Co, Cr, and Fe suggests it should be the high‐entropy FCC phase. Compared with the gray phase 2, the Si content in phase 3 is greatly increased because the Si atoms diffuse into the EHEA filler and react with Cr atoms to form the CrSi 2 phase 34,35 . Therefore, the phase 3 may be a mixture consisting of the FCC and CrSi 2 phases.…”

“…Compared with the gray phase 2, the Si content in phase 3 is greatly increased because the Si atoms diffuse into the EHEA filler and react with Cr atoms to form the CrSi 2 phase. 34,35 Therefore, the phase 3 may be a mixture consisting of the FCC and CrSi 2 phases. The dark gray phase 4 in Zone II has a similar chemical composition to the dark gray phase 1 in Zone I, which has been deduced as the Al 8 Cr 5 phase.…”

Heterogeneous material joining of sapphire and TC4 alloy with a functionally graded interface

“…However, this method still has intrinsic defects. Due to the low melting point of the solder, the joint cannot withstand a high temperature 14,15 . Secondly, active diffusion bonding is used.…”

“…Due to the low melting point of the solder, the joint cannot withstand a high temperature. 14,15 Secondly, active diffusion bonding is used. This method is characterized by the low cost and high efficiency.…”