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Abstract Graphene nanoplatelets (GNPs) were used as reinforcement in AgCuTi filler for brazing SiC ceramic. Ti from the filler reacted with SiC ceramic to form TiC and Ti 5 Si 3 adjacent to the SiC ceramic. According to the TEM and HRTEM results, TiC layer exhibited good lattice matching with SiC substrate. TiC particles synthesized by the reaction between Ti and GNPs in situ promoted the heterogeneous nucleation of TiCu and Cu(s,s), and contributed to the refinement of microstructure. Shear tests results indicated that the adoption of GNPs affected the joint property significantly. The TiC particles and an appropriate TiC + Ti 5 Si 3 layer thickness both relieved the residual stress of the brazed joint and thereby increased the joint strength. The shear strength of the joint reached the maximum value of 38 MPa when using AgCuTi/GNPs (GNPs reinforced AgCuTi) composite filler containing 1% GNPs, which was ∼139% higher than that of the joint brazed with AgCuTi filler. [ABSTRACT FROM AUTHOR]

In this work, alumina ceramic was bonded to itself with composite foils (Ti/Cu/Ni/Cu/Ti). The thermodynamics analysis indicates that Ti-Cu liquid firstly formed and reacted with alumina to produce Ti 3 Cu 3 O reaction layer. Meanwhile, the consumption of element Ti within the Ti-Cu liquid by Ni interlayer optimized the microstructure of the joint. By thickening Ni interlayer from 0 µm to 100 µm at 1020 ℃, the joints' strength could be significantly improved by 130.6%. While the joints' strength decreased with the decomposition of reaction layer at the brazing temperature higher than 1020 ℃. The FE simulations show that the high-level stress concentration within the reaction layer could be ameliorated by Ni interlayer effectively, which was in accordance with the corresponding fracture characteristics. Although the joint's strength could be improved to 203.9 MPa by using 300 µm Ni interlayer, its improvement rate was limited with Ni interlayer constantly thickening. [ABSTRACT FROM AUTHOR]

In this paper, AlN ceramic was directly joined to copper without active brazing filler metal. By exerting the nanosecond laser irradiation on the AlN surface, the AlN ceramic was thermally decomposed to aluminum and the surface was metalized. The as-metalized AlN ceramic was successfully joined to copper through the eutectic reaction between aluminum and copper. The effect of the groove interface structure fabricated with various laser scanning speeds on the mechanical and heat transfer properties of AlN/Cu joints was investigated. The joints obtained optimal shear strength and thermal diffusivity of 10.64 MPa and 51.75 mm2/s at the scanning speed of 250 mm/s. The micro groove structures of the interface contributed to the enhancement of mechanical and heat transfer properties of joints. The approach of laser-irradiation assisted joining proposed in this paper provided a novel thought for the fabrication of metal/ceramic composite structures. [ABSTRACT FROM AUTHOR]