Synthesis of TiB2-TiC-Ni/TiAl/Ti functionally gradient materials by FAPAS process

Field-activated pressure-assisted synthesis (FAPAS) was used to prepare TiB2-TiC-Ni/TiAl/Ti functionally gradient materials. Interfacial microstructure and bonding strength of materials were mainly investigated. The microstructure, phase composition and distribution of elements of interface were analyzed by SEM, XRD and EDS. The shear strength and micro-hardness were also tested. The results show that the particles of TiB2-TiC composite ceramics prepared by FAPAS are fine and homogeneous disperse. Closely metallurgical bonding forms between layers by mutual diffusion of different elements across the interfaces. The maximum shear strength of joint reaches 85.878 MPa and the fracture occurs at the interface of cermet and TiAl. The micro-hardness of the sample changes gradually from titanium substrate to the cermet with a maximum hardness of 2760HV in the cermet.