In-Situ Synthesis of (TiC)pNi/TiAl/Ti Functional Gradient Materials via Field-Activated Process

Abstract:

(TiC)PNi/TiAl/Ti functional gradient materials (FGMs) were prepared by field-activated pressure-assisted synthesis ( FAPAS) and in-situ synthesis processes. The roles of the electric field in material synthesis and diffusion bonding of layers were investigated. The microstructure and phase composition of each layer as well as component distribution of elements across the interfaces of the layers were analyzed by means of OM, SEM, EDS and XRD. The results show that the imposition of the electric field and the combustion reaction of TiAl is the key for the successful synthesis of FGMs; the TiC particles formed by in-situ synthesis process are fine and distributed uniformly; moreover, concentration profiles of elements across the interfaces of the layers show significant inter-diffusion and good metallurgical bonding. The sample has an excellent thermal shock resistance ability and gradient distribution of micro-hardness across the titanium substrate to the surface layer.