Finite element analysis of single-fiber push-out tests of continuous Al2O3 fiber-reinforced NiAl composites

An interface model of NiAl composites was developed, in which the thermal residual shear stress at the interface and the frictional stress at the interface were included to extract the intrinsic interfacial strength of NiAl composites. According to the finite element method (FEM) simulation, initial debonding can occur at the top or bottom side depending on sample thickness. The intrinsic interfacial shear strength of a NiAl composite without BN interlayer that exhibits good interface bonding after diffusion bonding is much higher than the one with BN interlayer that delaminated during cooling down after diffusion bonding due to development of texture in the BN interlayer. The introduction of BN interlayer results in the reduction of interfacial shear strength that is unexpected for load transfer of interface. The push-out test was also numerically simulated at elevated temperatures by assuming a constant value of the interfacial shear strength.