High alloy austenitic steels reinforced with ZrO2 are a promising class of composite materials for structural and tribological applications. Although martensitic transformations in both constituents of the composite enhance the mechanical properties and provide a damage tolerance capability, the interface suffers from deterioration during plastic deformation. By coating the ZrO2 particles with a thin Titanium layer in nm scale before sintering of the composite an intermediating interface is generated and the adhesion mechanisms are modified. The interdiffusion of the interface agent and the consequences on the local phase formation and the resulting microstructure of the composite are investigated using (HR)TEM, XRD, SEM, EBSD and XPS. Correlative mechanical tests will demonstrate the influence of the interface modification.