Carbon fiber-reinforced Carbon matrix composites were brazed to copper-clad molybdenum using two active Ag-Cu braze alloys, Cusil-ABA and Ticusil. The SEM and EDS examination of the brazed joints revealed good bonding and preferential precipitation of Ti at the composite/braze interface. Some tendency toward de-lamination was observed within resin-derived C-C composite due to its low inter-laminar shear strength. The inter-fiber channels between carbon fibers in the 3-D C-C composites were infiltrated with the molten braze. The Knoop hardness (HK) distribution across the joints was reproducible and revealed sharp hardness gradients at the Cu-clad-Mo/braze interface. Higher hardness was observed in Ticusil (approx 85-250 HK) than in Cusil-ABA (-50-150 HK). possibly due to the higher Ti content of Ticusil (4.5 percent Ti) than Cusil-ABA (1.75 percent Ti). Steady-state heal conduction calculations show that the joined assembly may have 22 percent lower thermal resistance compared to C-C composite of the same dimensions. This suggests that C-C/Cu-clad-Mo joints may be promising for thermal management applications.
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