The interfacial microstructures and mechanical properties of the joints formed by active cement added brazing in vacuum of C-f/SiC composite to Invar alloy, using Ag-Cu eutectic alloy and pure copper foil as braze alloy and interlayer respectively, were investigated. CuTi, Cu4Ti3, Fe2Ti and the reaction layer of TiC and Si were the predominant components at the joint interface. The maximum shear strength of the joint was 77 MPa for brazing at 850 degrees C for 15 min. The results show that active cement added brazing in vacuum using Ag-Cu eutectic alloy and Cu interlayer can be used successfully for joining C-f/SiC composites to Invar alloy. (C) 2012 Elsevier B.V. All rights reserved.