Interface study on the plasma sprayed monolayer NiAl composite reinforced with W fibers

The plasma sprayed monolayer NiAl composite reinforced with W fibers was prepared and the interfaces in the composite were also studied. The results show that W fibers and NiAl matrix have better inconsistency. The as-sprayed interface of W/NiAl is mechanically bonded and there is no interdiffusion or interface reaction. The bonding of W/NiAl interface is improved after annealing at 800°C for 3 h and the alumina layer between W/NiAl and the crystallized NiAl-droplets grows thicker after annealing at 1200°C for 48 h. Furthermore, the interdiffusion layer of W, Ni, Al elements is not created during two different annealing. In other respect, there are some inter-splats in NiAl matrix, which is composed of alumina and is produced by plasma sprayed processing. This interface is the weakly connected region of NiAl matrix and always induces the brittle fracture of NiAl matrix.