Design and Synthesis of Ti-ZrO₂ Functionally Graded Materials

Functionally graded materials (FGMs) based on titanium-zirconia system have been prepared by powder metallurgical method. The graded interlayer number and the compositional distribution have been designed by elastic finite element method. The interfacial microstructure between layers, the combining state of phases between Ti and ZrO₂ have been investigated by means of XRD (X-ray diffraction), SEM (scanning electron microscope), EDS (energy dispersive spectrometer) and so on. The co-existing region of Ti and ZrO₂ has been determined by thermodynamic calculation to control the sintering atmosphere. The experimental results show that the joint between Ti and ZrO₂ phases is physical in this composite and ZrO₂ mainly exists as tetragonal phase. The microstructure of Ti-ZrO₂ system FGM exhibits a transition from a zirconia particle dispersion in a titanium matrix to an inverse dispersion of titanium in zirconia. The gradient structure of titanium and zirconia can relieve thermal stress.